Answer:
B.
Step-by-step explanation:
1*77>0*27
77>0
Therefore 77 is greater than 0
(a) Given an initial condition for y0, answer the following questions, where yt is the random variable at time t,ε is the error, t is also the time trend in (iii):
(i) find the solution for yt, where yt=yt−1+εt+0.3εt−1.
(ii) find the solution for yt, and the s-step-ahead forecast Et[yt+s] for yt=1.2yt−1+εt and explain how to make this model stationary.
(iii) find the solution for yt, and the s-step-ahead forecast Et[yt+s] for yt=yt−1+t+εt and explain how to make this model stationary.
(i) To find the solution for yt in the given equation yt = yt−1 + εt + 0.3εt−1, we can rewrite it as yt - yt−1 = εt + 0.3εt−1. By applying the lag operator L, we have (1 - L)yt = εt + 0.3εt−1.
Solving for yt, we get yt = (1/L)(εt + 0.3εt−1). The solution for yt involves lag operators and depends on the values of εt and εt−1. (ii) For the equation yt = 1.2yt−1 + εt, to find the s-step-ahead forecast Et[yt+s], we can recursively substitute the lagged values. Starting with yt = 1.2yt−1 + εt, we have yt+1 = 1.2(1.2yt−1 + εt) + εt+1, yt+2 = 1.2(1.2(1.2yt−1 + εt) + εt+1) + εt+2, and so on. The s-step-ahead forecast Et[yt+s] can be obtained by taking the expectation of yt+s conditional on the available information at time t.
To make this model stationary, we need to ensure that the coefficient on yt−1, which is 1.2 in this case, is less than 1 in absolute value. If it is greater than 1, the process will be explosive and not stationary. To achieve stationarity, we can either decrease the value of 1.2 or introduce appropriate differencing operators.
(iii) For the equation yt = yt−1 + t + εt, finding the solution for yt and the s-step-ahead forecast Et[yt+s] involves incorporating the time trend t. By recursively substituting the lagged values, we have yt = yt−1 + t + εt, yt+1 = yt + t + εt+1, yt+2 = yt+1 + t + εt+2, and so on. The s-step-ahead forecast Et[yt+s] can be obtained by taking the expectation of yt+s conditional on the available information at time t.
To make this model stationary, we need to remove the time trend component. We can achieve this by differencing the series. Taking first differences of yt, we obtain Δyt = yt - yt-1 = t + εt. The differenced series Δyt eliminates the time trend, making the model stationary. We can then apply forecasting techniques to predict Et[Δyt+s], which would correspond to the s-step-ahead forecast Et[yt+s] for the original series yt.
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For the function below find a) the critical numbers; b) the open intervals where the function is increasing, and c) the open intervals where it is decreasing f(x)=8x³-42x-48x + 4 a) Find the critical number(s). Select the correct choice below and, if necessary fill in the answer box to complete your choice. A. The critical number(s) is/are (Type an integer or a simplified fraction. Use a comma to separate answers as needed
A) Function is increasing on (-∞, -1) and (7/2, ∞), and decreasing on (-1, 7/2).
b) The local minimum value of f is; 5608/2197 at x = -42/13, and the local maximum value of f is 139/8 at x = 7/2.
(a) To determine the intervals on which f is increasing or decreasing, we need to determine the critical points and then check the sign of the derivative on the intervals between them.
f(x)=8x³-42x-48x + 4
f'(x) = 24x² - 90
Setting f'(x) = 0, we get
24x² - 90 = 0
24x² = 90
x =± √3.75
So, the critical points are;
x = -1 and x = 7/2.
We can test the sign of f'(x) on the intervals as; (-∞, -1), (-1, 7/2), and (7/2, ∞).
f'(-2) = 72 > 0, so f is increasing on (-∞, -1).
f'(-1/2) = -25 < 0, so f is decreasing on (-1, 7/2).
f'(4) = 72 > 0, so f is increasing on (7/2, ∞).
Therefore, f is increasing on (-∞, -1) and (7/2, ∞), and decreasing on (-1, 7/2).
(b) To determine the local maximum and minimum values of f, we need to look at the critical points and the endpoints of the interval (-1, 7/2).
f(-1) = -49
f(7/2) = 139/8
f(-42/13) = 5608/2197
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Solve for x. Type your answer as a number in the blank without "x=".
The value of x in the given circle is 100°.
Given is a circle with an inscribed angle of 50°, we need to find the measure of the angle x which is the central angle,
Central Angle Theorem :-
Theorem: The angle subtended by an arc at the center of the circle is double the angle subtended by it at any other point on the circumference of the circle.
Therefore, x = 2 × 50°
x = 100°
Hence, the value of x in the given circle is 100°.
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Help me please thanks
Answer:
-5/6
Step-by-step explanation:
substitute the values
-4+9/-6
combine like terms
-5/6
3. Solve your equation to find the distance Jane’s trainer bikes. Show your work.
4. How much farther does Jane travel than her trainer?
(my previous answers so this will make sense)
1. The total distance jane bikes and runs is 28 miles.
2. Janes trainer bikes a distance of 20 miles.
Jane travels 8 miles much farther than her trainer. The solution is obtained using arithmetic operations.
What are arithmetic operations?
By combining operands with one arithmetic operator, an arithmetic operation is given. The built-in functions add, subtract, divide, and multiply additionally allow for the specification of arithmetic operations.
3. Using pythagoras theorem, we get the equation as D² = 12² + 16².
⇒D² = 144 + 256
⇒D² = 400
⇒D = √400
⇒D = 20
4. Jane has traveled 28 miles in total whereas her trainer has traveled 20 miles.
So, the difference is 28-20= 8 miles
Hence, Jane travels 8 miles much farther than her trainer.
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Julie started to solve the exponential expression (–2)3. (–2)3 = –2 ⋅ –2 ⋅ –2 = ? Which of these explains why Julie gets a negative number for her final answer? Question 25 options: The exponent 3 is an odd number. The base –2 is an even number. The base –2 is a negative number. The exponent 3 is a positive number.
Answer:
The base –2 is a negative number
Step-by-step explanation:
We need to solve the exponential expression (–2)³.
(–2)³ = -2×-2×-2
= -8
The final answer is -8. It is negative. It is because the base i.e. -2 is an even number. If the base is negative and the power is odd, the answer will be a negative number. Here, base is -2, power is 3. Hence, the correct option is (c) "The base –2 is a negative number".
Answer:
The exponent 3 is an odd number.
Step-by-step explanation:
Since the exponent (3) is an odd number, the answer will be negative. Answer: –8
Sidenote: I got this answer correct on the test :)))
6. Find the number of each category of voters based on the
information given below.
Total number of votes = 300000 votes
Percentage of
Votes, Others,
4%, 4%
Percentage
of Votes,
Females,
47%,
Percentage
of Votes
Males, 49%
Number of Male voters =
Number of female voters =
Number of voters to "Others" category=
The number of Male voters =14700, The number of female voters =14100 and the number of voters to "Others" category=1200
How do you calculate a percentage?
A % is a quantity or ratio that, in mathematics, represents a portion of one hundred. It's frequently represented by the sign "%" or just "percent" or "pct." For instance, the decimal 0.35, or the fraction, represents 35%.
Given : Total votes = 300000
males = 49%
females = 47%
Others = 4%
Number of votes for males = \(\frac{49}{100} *300000\) = 14700
Number of votes for females = \(\frac{47}{100} *300000\) = 14100
Number of votes for others = \(\frac{4}{100} *300000\\\) = 1200
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please ignore the numbers at the top.how do i graph this please help ASAP.
Answer:
(0,4) is the y-intercept and 3x is the slope
Can somebody help me, please
Answer:
uh I don't even know what this is
Answer: x = 500
Step-by-step explanation:
Use the Pythagorean Theorem
a²+b²=c²
300² + 400² = x²
90000 + 160000 = x²
250000 = x²
√250000 = √x²
500 = x
hope i explained it :)
The sum of the digits of a two digit number is 6z the number with its digits reversed is 18 less than the original number. Find the original number
Answer:
42
Step-by-step explanation:
Given:-
The Sum of the Digit of a Two Digit number is 6.
On reversing, the number is 18 less than the original number.
To Find:-
The original Number.
Let the Ones digit be "x"
ten's digit be = (6 - x)
Original Number = x + 10(6 - x) = 60 - 9x
Now, Atq.
One's Digit = (6 - x)
Ten's digit = x
New Number = 10 × x + (6 - x) = 9x + 6.
So,
(New Number) - (Original Number) = 18
(9x + 6 ) - (60- 9x) = 18
9x + 6 - 60 + 9x = 18
18x - 54 = 18
18x = 18 + 54.
18x = 72
x = 72/18
x = 4.
Therefore,
One's Digit = x = 4
Ten's digit = 6 - x = 2
Original Number = 42
43% of a sample of 100 visitors to a national park believes that additional funds should be used to preserve endangered species. what is the margin of sampling error for a 95% confidence interval?
The margin of sampling error for a 95% confidence interval is 9.7%
How to find the Margin of Error?The formula for margin of error here is;
E = z√(p(1 - p)/N)
where;
n is sample size
z is the z score
p is the sample proportion
z-score for a 95% confidence interval from tables is 1.96.
We are given;
p = 43% = 0.43
n = 100
Thus;
E = 1.96√(0.43(1 - 0.43)/100)
E = 0.097 = 9.7%
Thus, we can conclude that the margin of sampling error for a 95% confidence interval is 9.7%
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What is the constant rate of change in this?
Answer:
-1/2 or -0.5
Step-by-step explanation:
using y2-y1/x2-x1 on any two points: 2.5-5/1--4 = -1/2 or -0.5
Jayden has a bag that contains orange chews, cherry chews, and watermelon chews. He performs an experiment. Jayden randomly removes a chew from the bag, records the result, and returns the chew to the bag. Jayden performs the experiment 54 times. The results are shown below:
A orange chew was selected 18 times.
A cherry chew was selected 4 times.
A watermelon chew was selected 32 times.
If the experiment is repeated 1400 more times, about how many times would you expect Jayden to remove a watermelon chew from the bag? Round your answer to the nearest whole number.
Answer:
13 I think
Step-by-step explanation:
Geoff goes to the shop and buys a packet of crisps for 25p, a can of soup
for 68p and a watermelon for £1.47. He pays with a £5 note. How much
change does he get? Give your answer in pounds (£).
CRISPS
Salt & Vinegar
25p
SOUP
68p
£1.47
Answer:
Step-by-step explanation:
Geoff is feeling peckish, so he decides to pop into the shop and grab some snacks. He picks up a packet of crisps for 25p, a can of soup for 68p and a watermelon for £1.47. He wonders why the watermelon is so cheap, but he doesn't question it. He goes to the cashier and hands over a £5 note. The customer behind Geoff wonders "how much change does he get back?"
To figure this out, we need to add up the price of the snacks and take it away from the money Geoff gave. We can use a dot to show the pence as parts of a pound. For example, 25p = 0.25 pounds.
The price of the snacks is:
0.25 + 0.68 + 1.47 = 2.40 pounds
The money Geoff gave is:
5.00 pounds
The change is:
5.00 - 2.40 = 2.60 pounds
So, Geoff gets £2.60 in change and a bargain watermelon.
Answer:
Answer:
2.60
Step-by-step explanation:
25+68+147=240
500-240=260
turn into pounds 2.60
Step-by-step explanation:
let r be the region bounded by the graphs of y=sin(pi x) and y=x^3-4x as shown in the figure above
Area shaded represents the area bounded by both the graphs of the functions y = sin(πx) and y = x³ - 4x.
What is the area bounded by two curves?An area bounded by two curves is the area under the smaller curve subtracted from the area under the larger curve. This will get you the difference, or the area between the two curves.
Given is the region {r} bounded by the graphs of y = sin(πx) and y = x³ - 4x.
Refer to the graph attached. The shaded region is the area bounded by both the graphs of the functions y = sin(πx) and y = x³ - 4x.
Therefore, area shaded represents the area bounded by both the graphs of the functions y = sin(πx) and y = x³ - 4x.
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what is the slope of the line
Answer:
The slope is 0.8 or 4/5.
Step-by-step explanation:
Let's take two points on a line. (-2,0) and (3,4).
Now, determine the rise and run.
Rise: 4Run: 5Slope = Rise/Run
=> 4/5Conclusion:
Therefore, the slope is 0.8 or 4/5.
Hoped this helped.
\(BrainiacUser1357\)
Answer:
The answer is rise over run
Step-by-step explanation:
You divide the rise coordinate on the Y axis of the X coordinate
Question 1 (2 x 12 = 24 marks) Analyze and discuss the performance (in Big-O notation) of implementing the following methods over Singly Linked List and Doubly Linked List Data structures: To be submitted through Turnitin.Maximum allowed similaritv is 15% Operation Singly Linked List Doubly Linked List add to start of list Big-O notation Explanation add to end of list Big-O notation Explanation add at given index Big-O notation Explanation
In analyzing the performance of implementing the given methods over Singly Linked List and Doubly Linked List data structures, we consider the Big-O notation, which provides insight into the time complexity of these operations as the size of the list increases.
Add to Start of List:
Singly Linked List: O(1)
Doubly Linked List: O(1)
Both Singly Linked List and Doubly Linked List offer constant time complexity, O(1), for adding an element to the start of the list.
This is because the operation only involves updating the head pointer (for the Singly Linked List) or the head and previous pointers (for the Doubly Linked List). It does not require traversing the entire list, regardless of its size.
Add to End of List:
Singly Linked List: O(n)
Doubly Linked List: O(1)
Adding an element to the end of a Singly Linked List has a time complexity of O(n), where n is the number of elements in the list. This is because we need to traverse the entire list to reach the end before adding the new element.
In contrast, a Doubly Linked List offers a constant time complexity of O(1) for adding an element to the end.
This is possible because the list maintains a reference to both the tail and the previous node, allowing efficient insertion.
Add at Given Index:
Singly Linked List: O(n)
Doubly Linked List: O(n)
Adding an element at a given index in both Singly Linked List and Doubly Linked List has a time complexity of O(n), where n is the number of elements in the list.
This is because, in both cases, we need to traverse the list to the desired index, which takes linear time.
Additionally, for a Doubly Linked List, we need to update the previous and next pointers of the surrounding nodes to accommodate the new element.
In summary, Singly Linked List has a constant time complexity of O(1) for adding to the start and a linear time complexity of O(n) for adding to the end or at a given index.
On the other hand, Doubly Linked List offers constant time complexity of O(1) for adding to both the start and the end, but still requires linear time complexity of O(n) for adding at a given index due to the need for traversal.
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f(x)=x, g(x)=9+x, h(x)=3(x-7)+10x and the sum of 8 times the outputs of f and 4 times the outputs of g is equal to those of h
The value of x that satisfies the equation 8f(x) + 4g(x) = h(x) is x = 57.
The given functions are:
f(x) = x
g(x) = 9 + x
h(x) = 3(x - 7) + 10x
We are given that the sum of 8 times the outputs of f(x) and 4 times the outputs of g(x) is equal to the outputs of h(x).
Mathematically, this can be represented as:
8f(x) + 4g(x) = h(x)
Substituting the given functions, we have:
8x + 4(9 + x) = 3(x - 7) + 10x
Simplifying the equation:
8x + 36 + 4x = 3x - 21 + 10x
12x + 36 = 13x - 21
12x - 13x = -21 - 36
-x = -57
x = 57
Therefore, the solution to the equation is x = 57.
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Note the search engine cannot find the complete question .
ezra determined that the graph shown below is vertically compressed by a factor of 1/3 from the graph of y=|x| do you agree or disagree? why?
Answer:
Step-by-step explanation:
no graph was shown
Helen and Stephen both simplify the exponential expression 4 ln21 3 e −
Stephen makes the mistake in the expression as he uses the 4 in the root and the 3 in the power and the expression actually is: ∛(16)/e
How to illustrate the information?We start with the expression:
exp( (4/3)*ln(2) - 1)
Here we can use that:
exp(ln(x)) = x.
and e^(a + b) = e^a*e^b.
the first step here is:
e^((4/3)*ln(2) - 1) = e^((4/3)*ln(2)*e^(-1)
So the first step of Stephen is correct, but the first step of Helen is not, you can not simplify the expression in that way.
now, we have that:
a*ln(x) = ln(x^a)
then we can write:
(4/3)*ln(2) = ln(2^(4/3))
and e^(ln(2^(4/3)) = 2^(4/3)
then we have:
e^((4/3)*ln(2)*e^(-1) = 2^(4/3)/e
now we can write this as:
∛(2^4)/e
Here is where Stephen makes the mistake, he uses the 4 in the root and the 3 in the power.
The expression actually is: ∛(16)/e
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Select all the equations equivalent to
6x9=12
a )2x + 3 = 4
B)0x + 9 = 6
C)6x + 12 = 9
D) 3= 2x + 4
E)3x + 9 = 6
F)6x=3
Equation which is equivalent to the given equation 6x + 9 = 12 is given by 2x + 3 = 4.
As given in the question,
Given equation is equal to :
6x + 9 = 12
Simplify by writing each number into prime factors of the given equation 6x + 9 =12 to get the equivalent equation,
( 2 × 3 )x + ( 3 × 3 ) = ( 2 × 2 × 3 )
3 is the common factor in all we get,
3 ( 2x + 3) = 3(4)
Divide by 3 both the side of the equation we get,
2x + 3 = 4
Therefore, equation which is equivalent to the given equation 6x + 9 = 12 is given by 2x + 3 = 4.
The complete question is:
Which equation is equivalent to the equation 6x + 9 = 12?
A. x +9=6
B. 2x + 3 = 4
C. 3x + 9 = 6
D. 6x + 12 = 9
E. 6x = 3
F. 3 = 2x + 4
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can somebody help with step by step
Answer:
the range is 18.5
Step-by-step explanation:
14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 20, 21, 21, 22, 22, 22, 23, 24, 25, 26, 27.
Then take 1 off of the back and then take one from the front. (continue this until you find your answer)
If I am wrong feel free to yell at me and report me.
In a physics laboratory, a spring is fixed to the ceiling. With no weight attached to the end of the spring, the spring is said to be in its equilibrium position. As weights are applied to the end of the spring, the force stretches the spring a distanced from its equilibrium position. A student in the laboratory collects the following data: Foree F (Qb) 4 8 12 16 20 Distance d (cm) 10.0 20.0 30.0 40.0 50.0 a. Based on the data, do you suspect a direct relationship between force and distance or an inverse relationship? b. Find a variation model that describes the relationship between force and distance. Part 1 a. There appears to be a direct relationship between force and distance. Part 2 out of 2 b. The variation model is
The data suggests a direct relationship between force and distance in the spring experiment.
Based on the given data, as the force increases (4 N, 8 N, 12 N, 16 N, 20 N), the distance the spring stretches also increases (10.0 cm, 20.0 cm, 30.0 cm, 40.0 cm, 50.0 cm). This indicates a direct relationship between force and distance. In other words, as the force applied to the spring increases, the amount by which the spring stretches also increases.
To describe this relationship quantitatively, we can use Hooke's Law, which states that the force exerted by a spring is directly proportional to the displacement or stretch of the spring from its equilibrium position. Mathematically, Hooke's Law is expressed as F = k * x, where F is the force applied to the spring, k is the spring constant, and x is the displacement from the equilibrium position.
In the given data, the force (F) corresponds to the weight applied to the spring, and the distance (d) corresponds to the displacement. Therefore, the variation model that describes the relationship between force and distance in this experiment is F = k * d, where k represents the spring constant specific to the spring being used.
By analyzing the data and applying Hooke's Law, we can conclude that the force and distance have a direct relationship, and the variation model F = k * d represents this relationship.
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can someone help pls, giving brainlist to anyone, show work pls
Answer:
100
Step-by-step explanation:
We are given that ABC is similar to ZXY
This means Angle A is similar to Angle Z, Angle B is similar to Angle X and Angle C is similar to Angle Y.
Let's assume ABC is congruent to ZXY.
Angle A + Angle B + Angle C = 180
We can substitute Angle X for Angle B as they are congruent
Angle A + Angle X + Angle C = 180
50 + Angle X + 30 = 180
80 + Angle X = 180
Angle X = 100
What is the area, in square meters, of the trapezoid below? I need help please.
Answer:
48.72
Step-by-step explanation:
you would have to use area for a trapezoid formula! which is
A=(a+b)/2 x h plug in your units and you get 48.72
Find the surface area of each solid.
Answer:
232 in^2
Step-by-step explanation:
80 + 80 + 20 + 20 + 16 + 16 = 232
Check previous answer for better explanation!
A surveyor wants to know the length of a tunnel built through a mountain. According to his equipment, he is located 120 meters from one entrance of the tunnel, at an angle of 42° to the perpendicular. Also according to his equipment, he is 101 meters from the other entrance of the tunnel, at an angle of 28⁰ to the perpendicular. Based on these measurements, find the length of the entire tunnel. Do not round any intermediate computations. Round your answer to the nearest tenth. Note that the figure below is not drawn to scale. 120 meters 42° 28° 101 meters
The length of the entire tunnel is 127.88 meters by using cosine law or formulae.
Here we can use the formulae of cosine when two sides a and b and angle between then is given we can apply it.
\(c^{2} =a^{2} +b^{2} -2ab cos (\alpha )\)
Let us take surveyor as point A
one end of the tunnel denoted by point B
other end of the tunnel denoted by point C.
The length of AB is 101 meters
length of AC is 120 meters.
Measure of angle at point A = 42° + 28° =70°
Now lets find the length of tunnel
=\(\sqrt{(120^{2})+(101^{2})-2.(120)(101) cos (70) }\)
=\(\sqrt{14400+10201-24240(0.34)}\)
=\(\sqrt{24601-8246}\)
\(\sqrt{16355}\)
=127.88 meters.
Hence the length of the entire tunnel is 127.88 meters.
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Helen draws a random circle.
She then measures its diameter and circumference.
She gets a circumference, C, of 405 mm correct to 3 significant figures.
She gets a diameter, d, of 130 mm correct to 2 significant figures.
Helen wants to find the value of it using the formula n =
1 =
Calculate the lower bound and upper bound for Helen's value of .
Give your answers correct to 3 decimal places.
Answer:
lower bound: 2.996
upper bound: 3.244
Step-by-step explanation:
The value that Helen wants to use is Pi = C/D. The lower bound value is 3.065, and the upper bound for Helen's value is 3.165.
What is circumference?The circumference is the perimeter of the circle.
Given, the circumference, C, at 405 mm to three significant numbers.
She correctly estimates the diameter, d, to be 130 mm to two significant numbers.
Helen wants to find the value of Pi using the formula pi=C/D
We have, the circumference of the circle = C = 405 mm
The diameter of the circle = d = 130 mm
Pi = C/D
= 405 mm / 130 mm
= 405 / 130
= 3.115
3.115, measured to the nearest 0.1.
The degree of accuracy is nearest 0.1.
0.1/2 = 0.05
Upper bound = 3.115 + 0.05 = 3.165
Lower bound = 3.115 - 0.05 = 3.065
Therefore, the lower bound and upper bound for Helen's value are 3.165, and 3.065.
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If it takes 25 liters of gas to drive 150 miles, how many miles can be driven
using 35 liters of gas?
Answer:210 because 150 divided by 25 is 6 and 35 times 6 is 210
Step-by-step explanation:hope this helps : )
Can you please write a paragraph using this Key Terms: amphibians larvae salamanders emerge habitat dormant migrate escort
Answer:
DESCRIPTION: Large for a modern amphibian, the male California tiger salamander can reach up to 8.5 inches in length, the female up to seven. Adults have protruding eyes and long tails, and their slick bodies are mostly black with brilliant yellow spots and stripes on their back, sides, and tail. Larvae are greenish gray in color.
HABITAT: California tiger salamanders can be found in annual grasslands and oak woodlands with hot, dry summers and cool, rainy winters. For most of the year, they reside in underground burrows created and abandoned by small mammals. They need ephemeral pools for breeding.
RANGE: Historically these salamanders ranged throughout California's Sacramento and San Joaquin River valleys, the surrounding foothills, and the lower elevations of the state's central coast. Now their distribution is limited to disjunct vernal pool complexes in the northern part of their historical range. The northernmost and southernmost populations, residing in Sonoma and Santa Barbara counties respectively, are genetically distinct and geographically isolated from others.
MIGRATION: Once fall and winter rains begin, adult tiger salamanders emerge from underground hibernation habitat in mammal burrows and migrate to breeding ponds. After breeding, adults disperse back to uplands habitat to retreat underground. Adults may migrate long distances between summering and breeding sites: salamanders have been found along roads more than 1.2 miles from any known breeding ponds. Juvenile salamanders dispersing from ponds have been trapped more than 1,200 feet from their natal ponds.
BREEDING: Following early-winter rains, California tiger salamanders nocturnally emerge from their burrows and lay their eggs in newly formed vernal pools. After the eggs are fertilized internally, a female can lay up to 1,300, which she deposits individually or in small batches. Adults move back to their terrestrial burrows after breeding.
LIFE CYCLE: Within two weeks of egg fertilization, salamander larvae hatch, remaining in their natal pools for two to three months. By late spring or summer, once they reach metamorphosis, juveniles roam up to two miles away to hibernate in terrestrial habitat. Salamanders are thought to have lifespans of 10 years or more.
FEEDING: For the first six weeks of life, juveniles eat small crustaceans, algae, and mosquito larvae. Adult salamanders prey on aquatic insects, invertebrates, and tadpoles of Pacific tree frogs, California red-legged frogs, western toads, and spadefoot toads.
THREATS: The California tiger salamander is threatened by habitat destruction due to urban and agricultural development, habitat fragmentation, pesticides, hybridization with nonnative tiger salamanders, introduced diseases, and predation by nonnative species.
POPULATION TREND: Surveys showed that by 1993, the California tiger salamander had been extirpated from at least half of its historic localities. By 2004, only six tiger salamander meta-populations within 48 breeding ponds remained in Santa Barbara County, and by 2005, only seven viable tiger salamander breeding sites remained in Sonoma County.
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