A researcher wanted to know whether novels that are being written during the pandemic are of a different length than normal. She took ten novels written during the pandemic and found that they had a mean length of 345 pages (SD = 11). If the average length for a novel normally is 320 pages, conduct a 95% confidence interval for these data and use it to determine whether she should reject or fail to reject her null hypothesis. Don't forget to write your hypotheses for this problem as well.
Answers
a) Where the above conditions are given, this means that we can not reject the null hypothesis since the t-value = 0.31 and is greater thand the t-value which is 2.26
b) there is 95% confidence that the true mean lenght of novels written duing the pandemic falls within the range of 338 - 352 pages.
What is the calculation for the above?To test the above hypothesis , we used the two tailed t -test with a 95% confidence level.
T- value is computed as follows:
t = (sample mean - population mean)/ (sample Standard deviation/ √sample size)
Using the given values, we have:
t = (345/320)/(11/√10)
t = 0.31
Hence at 95% confidence leve, we have 2.26 as critical value.
Since 0.31 is less than the critical value, we cannot reject the null hypothesis.
B) to compute the 95% confidence interval for the mean lenght of the novels written during the pendemic:
Sample ± (t-value x standard error)
Where:
Standard Error is given as = Sample Standard Deviation / √Sample size
Thus:
Standard Error = 11/√10
SE = 3.48
The 95% confidence interval therefore is:
345 ± (2.26 x 3.48
= 339.1, 351.9
≈ 339, 352.
Hence, it is correct to state that there is 95% confidence that the true mean length of novels written during the pandemic falls within the range of 338 - 352 pages.
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Related Questions
HELPPPPPPPP!!!!!!!!!!!!
Answers
Answer:
able to be believed; convincing. hope this helped
Answer and Step-by-step explanation:
I'm not sure what was in the video, but I do know what this word means.
I would say that usually something that is credible is typically something like an ad. Usually in ads people to to convince and persuade someone to buy or do something that will promote something to happen, usually by buying a company's product.
When evaluating a source, it is important to look for things that indicate whether or not a source is something persuasive, and who the audience of this source is for. For example, if most of a source is opinionated, then it is probably a credible source that is trying to make you buy something.
So, if you are researching an article or information topic, it is important to look for the clues of a source being credible, as I mentioned above.
Once more, I'm not too sure what was in the video, but I hope this helps.
Pls do it plz plz plz DO IT THE NOW!!!!
Answers
Answer:
(2 , 30) & (4, 60)
Step-by-step explanation:
y = 15x
When x = 2 , y = 15*2 = 30
When x = 4 ; y = 15 *4 = 60
Determine that the value x=9 of the following expiration given x2+3x-5
Answers
Step-by-step explanation:
To determine the value of x that satisfies the expression x^2 + 3x - 5 when x = 9, we simply substitute 9 for x and evaluate the expression:
9^2 + 3(9) - 5 = 81 + 27 - 5 = 103
Therefore, when x = 9, the expression x^2 + 3x - 5 evaluates to 103.
rate my answer, please.
Could someone explain on how to solve ‘square root’ problems? I don’t really understand the subject.
Thanks!! ^^
Answers
Choose the graph that represents the following system of inequalities: y ≥ −3x + 1 y ≤ 1 over 2x + 3 In each graph, the area for f(x) is shaded and labeled A, the area for g(x) is shaded and labeled B, and the area where they have shading in common is labeled AB. Graph of two intersecting lines. Both lines are solid. One line f of x passes through points negative 2, 2 and 0, 3 and is shaded above the line. The other line g of x passes through points 0, 1 and 1, negative 2 and is shaded above the line. Graph of two lines intersecting lines. Both lines are solid. One line g of x passes through points negative 2, 2 and 0, 3 and is shaded below the line. The other line f of x passes through points 0, 1 and 1, negative 2 and is shaded above the line. Graph of two intersecting lines. Both lines are solid. One line passes g of x through points negative 2, 2 and 0, 3 and is shaded below the line. The other line f of x passes through points 0, 1 and 1, negative 2 and is shaded below the line. Graph of two intersecting lines. Both lines are solid. One line f of x passes through points negative 2, 2 and 0, 3 and is shaded above the line. The other line f of x passes through points 0, 1 and 1, negative 2 and is shaded below the line.
Answers
Answer:
Correct graph is C
Step-by-step explanation:
Given two inequalities are:
1. \(y\leq -3x+1\)
2. \(y\leq x+3\)
Step1 : Remove the inequalities
1. \(y=-3x+1\)
2. \(y=x+3\)
Step2 : Finding intersection points of equations
By solving linear equation
\(y=-3x+1=x+3\)
\(-3x+x+3\)
\(x=-0.5\)
Replacing value of x in any equations
we get,
\(y=x+3\\\)
\(y=-0.5+3\)
\(y=2.5\)
Therefore, Point of intersection is (-0.5,2.5)
Step3: Test of origin (0,0)
Here, If inequalities holds true for origin then, shades the graph towards the origin.
For equation 1.
\(y\leq -3x+1\)
\(0\leq -3(0)+1\)
\(0\leq +1\)
True, Shade graph towards origin.
For equation 2.
\(y\leq x+3\)
\(0\leq 0+3\)
\(0\leq 3\)
True, Shade graph towards origin.
Thus, Correct graph is C
am I right for part A. And please help me with B
Answers
a) The radius of the sphere is given as follows: 27.13 ft.
b) The surface area can be checked as follows: S = 4 x 3.14 x 27.13² = 9244.
How to obtain the surface area?The surface area for a sphere of radius r is given by the equation presented as follows:
S = 4πr².
The surface area for this problem is given as follows:
9244 ft².
Hence the radius is given as follows:
\(r = \sqrt{\frac{9244}{4 \times 3.14}}\)
r = 27.13 ft.
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John has a job parking cars. He earns a fixed weekly salary of $180 plus a fee of $3 for each car he parks. His potential earnings for a week are shown in the graph. At what point does John begin to earn more from fees than his fixed salary? Complete the justification of your answer. Earnings 800 Weekly Earnings 395 300 225 150 S Cars parked 10 40 50 50 70 SO 90 100 John earns the same in fees as his fixed salary when he parks si - S fee per car = cars. He starts earning more from fees than his salary when he parks cars.
Answers
In order to determine at what point does John begin to earn more from fees than his fixed salary, consider that the weekly fixed salary is $180. Then it is necessary that John earns more than $180 from fees.
In the graph the searched point is the point with a salary of mores than
2x180 = 360 becasue for this salary John earns more from fees that from his fixed salary.
You can notice that from 60 cars parked the John's salary is at least $360.
Then, for the point (60,360) John earns more from fees than his fixed salary.
The train en español
Answers
Answer:
El tren
Step-by-step explanation:
El tren in Spanish translates to "the train"
Answer:
El tren
:) hopefully this helps
In the transmission of digital information, the probability that a bit has high, moderate, and low distortion is 0.02, 0.07, and 0.91, respectively. Suppose that three bits are transmitted and that the amount of distortion of each bit is assumed to be independent. Let and denote the number of bits with high and moderate distortion out of the three, respectively. Determine the following:
A. fxy(x,y).
B. fx(x).
C. E(X).
D. Are X and Y independent?
Answers
Answer:
A. (Table Attached)
B. (See Step 3)
C. 0.06 (See Step 4)
D. NOT independent (See Step 5)
Step-by-step explanation:
STEP 1:Name the probabilities:
p₁ = 0.02, p₂ = 0.07, p₃ = 0.91
q₁ = 1-p₁ = 0.98 , q₂ = 1-p₂ = 0.93 , q₃ = 0.09
Let X and Y be the number of bits with high and moderate distortion out of three.
STEP 2:A.
The function will follow multinomial distribution:
\(f_{XY}(x,y) = P(X=x, Y=y) = \frac{3!}{x!y!(3-x-y)!} (p_1^x)(p_2^y)(p_3^{3-x-y})\)
Substitute the values and make a table.
TABLE IN ATTACHMENT
STEP 3:
B.
We calculate marginal distribution by:
\(P (X=x)=\) ∑ \(P(X=x,Y=y)\)
\(fx(x)\) can be found by adding all the probabilities in each row for different value of X
For X=0 , ∑P = 0.94157441
For X=1 , ∑P = 0.057624
For X=2 , ∑P = 0.001176
For X=3 , ∑P =0.000008
STEP 4:C.
The mathematic expectation E is the sum of product of each possibility with its probabiity.
\(E(X)=\)∑ \(xP(X=x)\)
Find E(X):
\(E(X)= (0*0.9415744)+(1*0.057624)+(2*0.001176)+(3*0.000008)\)
\(E(X)=0.06\)
STEP 5:
Condition probability states:
\(P(A|B)=\frac{P(A,B)}{P(B)}\)
It can also be written as:
\(f_{Y|X=1}(y)=\frac{f_{XY}(1,y)}{f_x(1)}\)
Where \(f_x(1)\\\) = 0.057624
Calculate the quotient:
\(Y|_{x=1}\) = 0 , \(f_{Y|_X=1\) = 0.862245
\(Y|_{x=1}\) = 1 , \(f_{Y|_X=1\) = 0.132653
\(Y|_{x=1}\) = 2 , \(f_{Y|_X=1\) = 0.000510
\(Y|_{x=1}\) = 3 , \(f_{Y|_X=1\) = 0
Find the dependency:
\(f_{XY}(y)=f_X(x)f_Y(y)\)
We found that
\(f_{Y|_X=1\) = 0.862245
Calculate \(f_Y(1)\) from summing the column from the table
\(f_Y(1)=0.17428341+0.007644+0.000084\\f_Y(1)=0.18201141\)
Which are not equal.
Conclusion:
X and Y are NOT Independent
Based on the information in the table, what
was the approximate value of this item in
1980?
Answers
Answer:
B) 4,700
Step-by-step explanation:
6000 - 4000 = 2000
2000 in 15 year, find how much for each year
2000/ 15 = 133.3333333
133.3333333 estimated = 133
133 approximately for each year
1975 to 1980 is five years
133 x 5 = 665
4000 + 665 = 4665
4665 rounded the the nearest hundred
4700
Can I get help on this question? Please explain the process of how to solve it too.
Answers
Answer:
x = 13
y = 18.38
Step-by-step explanation:
tan 45 = x/13 (tangent = opposite / adjacent)
1 = x/13
multiply both sides by 13
x = 13
cos 45 = 13/y (cosine = adjacent / hypotenuse
0.7071 = 13/y
multiply both side by y
0.7071y = 13
divide both side by 0.7071
y = 18.38
Sierra says that she can simplify the left side of the inequality shown by combining the terms within the parentheses but that she can't do the same thing on the right side. Is Sierra correct? Explain.
4(-4 + 9) + 1 ≥ -2(y + 7) - 8
Answers
Answer: Yes, Sierra is correct.
Step-By-Step Explanation:
The parenthesis on the left side is (-4+9). This can be combined because both terms are two constants. Constants are any terms in a algebraic equation or inequality whose value does not changed and is pre-defined. In this parenthesis, the answer would be 5.
The parenthesis on the right side contains one constant (7) and one variable (y). Since you can only combine like terms, y and 7 cannot be combined. Therefore, you cannot combine the right-side parenthesis.
So, Sierra is correct
Evaluate 4|-2| - |-3|. Helpppp plz
Answers
Answer:
5
Step-by-step explanation:
Find Matrix mixed questions
Answers
The only matrix that is certainly symmetric is a)\((a^2 - b^2).\)
We know that a matrix A is symmetric if it is equal to its transpose, that is \(A = A^T.\)
a) \((a^2 - b^2)\)
We can write the transpose of this matrix as
\((a^2 - b^2)^T = (a^2)^T - (b^2)^T = a^2 - b^2\), which is equal to the original matrix. Therefore, this matrix is symmetric.
b) (A+B)(A-B)
Expanding this expression, we get \((A+B)(A-B) = A^2 - AB + BA - B^2.\)
Taking the transpose of this, we get \((A^2)^T - (AB)^T + (BA)^T - (B^2)^T = A^2 - BA + AB - B^2.\)
Since AB and BA may not be equal, we cannot say for certain that this matrix is symmetric.
c) ABA
Taking the transpose of this matrix, we get\((ABA)^T = A^T B^T A^T\). Since \(A^T and B^T\) may not commute, we cannot say for certain that this matrix is symmetric.
d) ABAB
Taking the transpose of this matrix, we get \((ABAB)^T = B^T A^T B^T A^T\). Again, since \(A^T and B^T\) may not commute, we cannot say for certain that this matrix is symmetric.
Therefore, the only matrix that is certainly symmetric is a) \((a^2 - b^2).\)
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A 22 km walk is completed in 5 hours and 30 min.
What is the average speed?
Answers
Answer:
121 km\hr
Step-by-step explanation:
displacement=speed÷time
then. speed = displacement×time
= 22 × 5.5
= 121 km\hr
please say the answer step by step
2(10-4)2square+8
Answers
Step-by-step explanation: here are the steps .
2(6)²+8
2×36+8
72 +8=80
So we made 6 to the power of 2 is 36 so 36 times 2 equals 72 so 72 plus 8 equals 80 . Hope this helps buddy. Please mark brainliest
How do you make a 10 in math?
Answers
To make 10 in math we have to break numbers such that they sums up in multiple of 10.
When learning their basic addition facts in the first grade, kids use the "create a ten" approach to help them understand addition facts that could otherwise be challenging to remember, like 8 + 4 or 9 + 5. Students apply the technique by breaking down one of the addends to create ten from the other.
Like if we have to add 7+4 then what we can do break 4 as 3+1 and then add 7+3 =10 then add 1 into it 10+1 = 1 which is 7+4.
When students work with greater numbers, the make a ten technique can be expanded. Consider adding 37 by 14. Do you understand how 7 + 4 are related? By breaking down 14 into 3 and 11, adding the 3 to 37 to create 40, then adding 40 + 11 to get 51, we might use the make a ten method.
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The average home price in Massachusetts is $410,000, with a standard deviation of $65,000. A city planner is studying the distribution across the state of home prices in the bottom 10%. What price will indicate that a home is in the bottom 10% if the city planner examines 200 homes around the state
Answers
Answer:
\(P(z<\frac{a-\mu}{\frac{\sigma}{\sqrt{n}}})=0.1\)
And replacing the value obtained we got:
\(z=-1.282<\frac{a-410000}{\frac{\sigma}{\sqrt{200}}}\)
And if we solve for a we got
\(a=410000 -1.282*\frac{65000}{\sqrt{200}}=404107.68\)
Step-by-step explanation:
Let X the random variable that represent the average home prices of a population, and for this case we know the distribution for X is given by:
Where \(\mu=410000\) and \(\sigma=65000\)
For this part we want to find a value a, such that we satisfy this condition:
\(P(X>a)=0.90\) (a)
\(P(X<a)=0.10\) (b)
We want to find a value who accumulate 0.10 of the area on the left and 0.90 of the area on the right of the normal standard distributon and for this case it's z=-1.282
And using the distribution for the sample mean we can do this:
\(P(X<a)=P(\frac{X-\mu}{\frac{\sigma}{\sqrt{n}}}<\frac{a-\mu}{\frac{\sigma}{\sqrt{n}}})=0.10\)
\(P(z<\frac{a-\mu}{\frac{\sigma}{\sqrt{n}}})=0.1\)
And replacing the value obtained we got:
\(z=-1.282<\frac{a-410000}{\frac{\sigma}{\sqrt{200}}}\)
And if we solve for a we got
\(a=410000 -1.282*\frac{65000}{\sqrt{200}}=404107.68\)
Answer:
Step-by-step explanation:
through: (5, 5), slope = 10
Answers
Answer: The correct answer is y = 10x – 45
Step-by-step explanation:
When graphing a line with a slope of 10 from point (5,5), we find that the y-intercept (where the line crosses the y-axis) is -45
Use the slope-intercept form (y=mx+b), where m=slope (10) and b=the y-intercept (-45)
y = 10x - 45
what is the equation of a vertical ellipse with a major axis= 20 and a minor axis = 14?
Answers
\(\bold{\text{Answer: b.}\quad \dfrac{y^2}{100}+\dfrac{x^2}{49}=1}\)
Step-by-step explanation:
The ellipse is vertical so y has the biggest radius.
Major axis (y) = 20 so the y-radius is 20/2 = 10
Minor axis (x) = 14 so the x-radius is 14/2 = 7
The equation of an ellipse is: \(\dfrac{(x-h)^2}{a^2}+\dfrac{(y-k)^2}{b^2}=1\) where
(h, k) is the center of the ellipsea is the x-radiusb is the y-radiusGiven: a = 7, b = 10
Assume: (h, k) = (0, 0)
\(\dfrac{(x-0)^2}{7^2}+\dfrac{(y-0)^2}{10^2}=1\\\\\\\dfrac{x^2}{49}+\dfrac{y^2}{100}=1\\\\\\\longrightarrow \dfrac{y^2}{100}+\dfrac{x^2}{49}=1\)
estimated work cost [it is a time-dependent variable cost related to manpower project resources and the time they are utilized. equipment when associate with time usage (i.e., hourly rentals) is also classified as work.]
Answers
The total estimated work cost for the project would be $5200 ($5000 + $200).
The formula for calculating the estimated work cost for a project is C = P x T, where C is the estimated cost, P is the hourly rate of the personnel and T is the total amount of time spent working on the project. For example, if the hourly rate of a project manager is $50 and they work 100 hours on the project, the estimated work cost would be $5000 (50 x 100). In addition, any equipment that is used on an hourly rental basis should also be included in the estimated work cost calculation. For example, if a piece of equipment is used for 10 hours at a rate of $20 per hour, the estimated cost for this equipment would be $200 (20 x 10). Therefore, the total estimated work cost for the project would be $5200 ($5000 + $200).
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b. A 50A by 35ft residential
garden produces 1975
servings of food over the
course of a year. How many
servings of food per square
foot is this?
Answers
Answer:
1.13 food per square feet
Step-by-step explanation:
Given
Dimension: 50ft by 35ft
Servings = 1975
Required
Determine the amount per servings
First, we calculate the area.
\(Area = 50ft * 35ft\)
\(Area = 1750ft^2\)
Next, we calculate the amount per square foot.
This is:
\(Rate = \frac{Serivings}{Area}\)
This gives;
\(Rate = \frac{1975}{1750}\)
\(Rate = 1.13\)
12. After 2 hours, Morgan had earned $12.75 at her lemonade stand. After 5
hours, she had earned $44.25. Assuming a linear function, write an
equation in the form y=mx+b that shows the profit earned from selling
lemonade for x hours.
Answers
Answer:
y = 10.5x - 8.25
Step-by-step explanation:
m = (44.25 - 12.75)/(5 - 2) = 10.5
y = mx + b
y = 10.5x + b
12.75 = 10.5 × 2 + b
b = -8.25
y = 10.5x - 8.25
A triangle has sides with lengths of 60 feet, 63 feet, and 87 feet. Is it a right triangle?
Answers
Answer:
Yes
Step-by-step explanation:
We can use the Pythagorean Theorem to check if this triangle is a right triangle:
\(a^2+b^2=c^2\)
Note that \(a\) and \(b\) are the legs of the triangle and \(c\) is the hypotenuse:
Substitute the lengths of the sides into the equation:
\(60^2+63^2=87^2\)
\(3600+3969=7569\\7569=7569\)
Therefore this triangle is a right triangle.
Find the product. (3.5(-3.4)
Answers
Answer:
-11.9
Step-by-step explanation:
Write an equation of the line shown. Then use the equation to find the value of 2 when y = 185
Answers
Answer:
\( y = 15x + 20 \)
x = 11, when y = 185
Step-by-step explanation:
Given:
(0, 20);
(2, 50)
Required:
Equation of the line;
Value of x, when y = 185
SOLUTION:
Equation of the line can be written using the slope-intercept formula, given as, \( y = mx + b \).
m = slope = \( \frac{y_2 - y_1}{x_2 - x_1} =\frac{50 - 20}{2 - 0} = \frac{30}{2} = 15 \)
b = y-intercept = the pointt at which the line cuts the y-axis = 20
Plug in the value into the formula to get the equation:
\( y = mx + b \)
\( y = 15x + 20 \)
Use this equation to solve for x, when y = 185
\( y = 15x + 20 \)
\( 185 = 15x + 20 \) (substitution)
\( 185 - 20 = 15x + 20 - 20 \)
\( 165 = 15x \)
\( \frac{165}{15} = \frac{15x}{15} \)
\( 11 = x \)
x = 11, when y = 185
Use the model below to calculate 9÷1/3.
A green rectangle is divided into 9 equal parts arranged into 3 rows of 3 cells each.
A.
9/3
B.
3/9
C.
13 1/2
D.
27
Answers
Using thie model ,The answer is D. 27.
To calculate 9÷1/3 using the model below, we can imagine dividing the green rectangle into thirds vertically. Each third would contain 3 cells.
Then, we can see that there are a total of 9 cells in the rectangle. Since we are dividing by 1/3, we need to find out how many sets of 1/3 are in 9.
We can see that there are 3 sets of 1/3 in each row (since each row contains 3 cells, which are thirds). So, in total, there are 3 rows of 3 sets of 1/3, which gives us:
9÷1/3 = 3 rows x 3 sets of 1/3 = 9 sets of 1/3 = 27
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a survyer was conducted amount 25 young adults to determine how many of them exercised during the week four people they exercised four days a week five people said they excersized five days a week what percentage exercised four or five days per week
Answers
The percentage of young adults who exercised four or five days a week is 36%
Out of the 25 young adults surveyed, a total of 4 people exercised four days a week and 5 people exercised five days a week. To calculate the percentage of young adults who exercised four or five days a week, we add the number of people who exercised four days a week to the number of people who exercised five days a week, which gives us a total of 9.
We then divide this by the total number of people surveyed (25) and multiply by 100 to get the percentage.
So the percentage of young adults who exercised four or five days a week is
(9/25) x 100 = 36%
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Find the probability of rolling a sum of two dice that is a 7 or a 12. Round answer to 4 decimal places
Answers
Answer:
The probability is 0.1944
Step-by-step explanation:
Since we are rolling two dice, the number of possible results is 36
for us to get a sum of seven, these are the possible results;
1 and 6
6 and 1
2 and 5
5 and 2
3 and 4
4 and 3
The probability of rolling a sum of 7 is 6/36
For a sum of 12, we only have one possible result and that is 6,6
So the probability here is 1/36
If we have or in probability, we add up the individual probabilities
So, our probability here will be;
1/36 + 6/36
= 7/36 = 0.1944
Triangle X(1, 6), Y(5, -2), Z(-5, -1) is mapped onto Δ
Δ
XʹYʹZʹ by a dilation with center (1, -2) and a scale factor of 3. Which function represents this dilation?
(x, y) → (1 + 3(x + 1), -2 + 3(y + 2))
(x, y) → (1 + 3(x - 1), -2 + 3(y - 2))
(x, y) → (1 + 3(x - 1), -2 + 3(y + 2))
(x, y) → (x + 3, y - 6)
30 points
Answers
On solving the provided question we can say that by herons formula, area of the triangle is, A = 2.828
What is triangle?A triangle is a polygon since it has three sides and three vertices. It is one of the basic geometric shapes. The name given to a triangle containing the vertices A, B, and C is Triangle ABC. A unique plane and triangle in Euclidean geometry are discovered when the three points are not collinear. Three sides and three corners define a triangle as a polygon. The triangle's corners are defined as the locations where the three sides converge. 180 degrees is the result of multiplying three triangle angles.
the provided points are Triangle X(1, 6), Y(5, -2), Z(-5, -1)
by herons formula
A = \(\sqrt{s(s-a)(s-b)(s-c)}\)
s = a+b+c/3
s = 5+2+5+/3 =12/3 = 4
Area of the triangle is, A =
\(\sqrt{4(5-4)(4-2)(5-4)} \\A = \sqrt{4*1*2*1} \\A = \sqrt{8} \\A = 2\sqrt{2}\\ A = 2*1.414\\A = 2.828\)
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Answer:
2.828
Step-by-step explanation: