if the mass of a sample of radioactive bismuth-214 decays from 87.7 micrograms to 24.6 micrograms in 36.1 minutes, what is the half-life of bismuth-214?

Answer:

20.04 is the answer lllaldjcnejchwh

An equation represent the given scenario is 4.99x=100.

In mathematics, an equation is a formula that expresses the equality of two expressions, by connecting them with the equals sign =.

Given that, Mark has a $100 gift card to buy apps for his smartphone.

Let the number of weeks be x.

Now, 4.99x=100

Therefore, an equation is 4.99x=100.

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"Your question is incomplete, probably the complete question/missing part is:"

Mark has $100 gift card to buy apps for his smartphone. Each week, he buys one new app for $4.99. Write an equation that relates.

Answer:

x2+2x−132x2+16

Step-by-step explanation:

First, let's simplify the expression by combining like terms:

x - 7x^2 + 8 - x^2 - x + 6x^2 + 8

= -7x^2 + 5x^2 - x^2 + x + 16

= -x^2 + 2x + 16

Now we need to factor the quadratic expression -x^2 + 2x + 16. We can use the quadratic formula or complete the square to find the roots, but it turns out that the expression doesn't factor nicely. However, we can rewrite it as -(x^2 - 2x - 16) and then use the quadratic formula to find the roots of the expression inside the parentheses:

x = (-(-2) ± sqrt((-2)^2 - 4(-16)))/(2(1))

x = (2 ± sqrt(68))/2

x = 1 ± 2sqrt(17)/2

x = 1 ± sqrt(17)

So we have:

-x^2 + 2x + 16 = -(x - (1 + sqrt(17)))(x - (1 - sqrt(17)))

Therefore, the expression is equal to -x^2 + 2x + 16, which corresponds to the option:

x^2 + 2x - 13 / 2x^2 + 16

Answer:

the answer is H=3 miles

Step-by-step explanation:

Area of Trapezoid = \({(Base1+Base2)/2 }* (Height)\)

we sub the values we have in the formula:

18= ( 5+7)/2 * (H)

H = (2*18)/(5+7)

H = 3 miles

where is H is the Height

(C) The standard deviation is 100 and the mean is 22.

The standard deviation is a statistic that expresses how much variance or dispersion there is in a group of numbers.

While a high standard deviation suggests that the values are dispersed throughout a wider range, a low standard deviation suggests that the values tend to be close to the established mean.

So, using the concepts of expected value and variance of random variables, this issue can be resolved.

By the expected value principle:

E(Y) = E(2+4X) = E(2) + E(4X) = 2 + 4E(X) = 2 + 4(5) = 22

\(\mathrm{E}(\mathrm{Y})=\mathrm{E}(2+4 \mathrm{X})=\mathrm{E}(2)+\mathrm{E}(4 \mathrm{X})=2+4 \mathrm{E}(\mathrm{X})=2+4(5)=22\)

Then, μy = 22

In terms of variance concept:
Var(Y) = Var(2 + 4x) = Var(2) + Var(4x) + 2Cov(2, 4x)

Cov(2, 4x) = 0

Var(2) = 0

Hence:
Var(Y) = Var(4x) = 4²Var(X) = 16σ²ₓ = 16(25²) = 10000

Standard deviation(Y) = √10000 = 100

Therefore, (C) the standard deviation is 100 and the mean is 22.

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Complete question:
The random variable X is normally distributed with a mean of 5 and a standard deviation of 25. The random variable Y is defined by Y = 2 + 4X. What are the mean and the standard deviation of Y? The mean is 20 and the standard deviation is 102.

A) The mean is 20 and the standard deviation is 50.

B) The mean is 22 and the standard deviation is 102.

C) The mean is 22 and the standard deviation is 100.

D) The mean is 22 and the standard deviation is 50.

Answer:

a) 6x + 8 = 32

Step-by-step explanation:

Forming algebraic equation:

Let the number be 'x'.

      6 times x = 6 * x = 6x

6x is added to 8: 6x + 8

         6x + 8 = 32

Answer:

225 coins

Step-by-step explanation:

9----------4%

x------------100%

Cross multiplication

4x = 900

x=225

Answer:

w = 10

Step-by-step explanation:

First we take the two values for the breadth of the rectangle

So:

5x - 9 = 3x + 7

now we solve this equation as follows:

5x - 3x = 9 + 7

2x = 16

x = 8

now that we have found the value for x, we can substitute it in the equation, 5x - 9,or in the equation, 3x + 7.

when we substitute x in any of these equations, we get

5(8) - 9 = 31

3(8) + 7 = 31

now that we have the value for the breadth we can form the following equation:

31 × w = 310

31w = 310

w = 310/31 = 10

Answer:

10

Step-by-step explanation:

Firstly, we find the value of X

since 5X-9 and 3X+7 are lenghts

5X-9= 3X+7

5X-3X= 7+9

2X = 16

dividing bothsides by 2

2X/2= 16/2

X = 8

Hence,

5X-9= 5(8)-9= 40-9 = 31

3X+7=3(8)+7= 24+7= 31

To find the width

Area= lenght×width

310= 31×w

31w= 310

w= 310/31

W= 10

Answer:

Modeling the situation with a quadratic equation, it is found that:

The maximum height of the ball is of 60.2 feet.

The ball hits the ground after 3.39 seconds.

Considering the gravity, the height of the ball, after t seconds, is given by the following quadratic equation.

In which:

is the initial velocity.

is the initial height.

In this problem:

Height of 8 feet, thus .

Initial velocity of 32 feet per second,  

The equation is:

Which is a quadratic equation with .

The maximum height is the output of the vertex, which is:

Then, with the coefficients of this question:

The maximum height of the ball is of 60.2 feet.

It hits the ground at t for which , thus:

We want the positive value, so:

The ball hits the ground after 3.39 seconds.

A similar problem is given at brainly.com/question/24626341

Step-by-step explanation:

we know that

The distance between ywo points is giving by the formula

in this problem we need to calculate the distance between B and C

so

looking at the graph

B(-35,-20)=(x1,y1)

C(-20,5)=(x2,y2)

substitute in the formula

Answer:

The answer is 0.0000034

Step-by-step explanation:

Answer:

136.99

Step-by-step explanation:

Đây là một câu hỏi dễ chỉ cần sử dụng máy tính

Answer:

(-2,-9)

(-1,8)

(0,-5)

(1,0)

(2,7)

Step-by-step explanation:

Answer:

Is 50

Step-by-step explanation:

I don’t know

Answer:

31.4 yards

Step-by-step explanation:

credits: ApusApus

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Answer:

Step-by-step explanation:

hello : here is an solution

Answer:

2 + 3 + 4 − 1 ⋅ 1 2 = 1 0

2 + 3 + 4 − 1 2 = 1 0

Step-by-step explanation:

Answer:

a/8 or a over 8 hope this helps

Step-by-step explanation:

Answer:

n

8

→

I used

n

as the unknown number

Explanation:

The quotient is the result of division between two numbers.

The quotient of a number (I used

n

) and

8

would be

n

8

Answer:

3. 6

4. 9

5. 12

6. 15

Step-by-step explanation:

Answer: 5

Step-by-step explanation: 180-175=5

The rejection region is not given in the question, so we cannot determine the type of error that can occur when the true survival rate is 50%.

However, we can calculate the probability of making a Type I error (rejecting the null hypothesis when it is actually true) and a Type II error (failing to reject the null hypothesis when it is actually false) for a given rejection region.

Assuming a significance level of 0.05, the rejection region for a one-tailed test of whether the true survival rate is greater than 40% is  with 19 degrees of freedom.

If the true survival rate is actually 50%, the probability of making a Type I error (rejecting the null hypothesis that the true survival rate is 40%) is 0.05, which is the significance level.

The probability of making a Type II error (failing to reject the null hypothesis that the true survival rate is 40% when it is actually 50%) depends on the true survival rate and the sample size. A larger sample size would decrease the probability of making a Type II error.

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i)It ended at  21:13

ii) 440*10/100

44 mins longer

The percentage is calculated by dividing the required value by the total value and multiplying by 100.

110% = 440 minutes (Tuesday journey)

100% = 100/110 x 440

100% = 400 minutes (Monday journey)

Tuesday's journey took 40 minutes longer than Monday's journey.

The percentage is calculated by dividing the required value by the total value and multiplying by 100.

Example:

Required percentage value = a

total value = b

Percentage = a/b x 100

We have,

On Tuesday the train journey took 7 hours and 20 minutes and began at

13:53.

The time train journey ended.

= 13:53 + 7 hours + 20 minutes

= 13 hours + 53 minutes + 7 hours + 20 minutes

= 20 hours + 73 minutes

= 20 hours + 60 minutes + 13 minutes

= 20 hours + 1 hour + 13 minutes

= 21 hours + 13 minutes

This means,

= 21:13

The train ended the journey at 21:13

Tuesday's time of 7 hours and 20 minutes was 10% more than Monday's journey time.

This means,

Converting into minutes.

7 hours 20 minutes

= 60 x 7 + 20 minutes

= 420 minutes + 20 minutes

= 440 minutes

Monday's journey time.

110% = 440 minutes:

100% = 100/110 x 440

100% = 400 minutes

Thus,

Tuesday's journey took 40 minutes longer than Monday's journey.

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Answer:

x = 11

Step-by-step explanation:

Take the fifth root on both sides.

27(x-2) = 3^5

27x-54 = 3^5

27x = 243 + 54

27x = 297

x = 297/27

x = 11

Answer:

\(x = 11 \\ \)

Step-by-step explanation:

\( \sqrt[5]{27(x - 2)} = 3 \\ { (\sqrt[5]{27(x - 2} )}^{5} = {3}^{5} \\ 27(x - 2) = 243 \\ 27x - 54 = 243 \\ 27x = 243 + 54 \\ 27x = 297 \\ \frac{27x}{27} = \frac{297}{27} \\ x = 11\)

Answer:

(b) 15/50

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

In this question:

There are 25+15+10 = 50 small balls.

Of those, 15 are blue.

Probability of taking a blue ball:

15/50

This means that (b) is the correct answer.

Answer:

(-5, 1.5)

Step-by-step explanation:

(-2 ,-1) ; (-8 , 4)

Midpoint = \((\frac{x_{1}+x_{2}}{2},\frac{y_{1}+y_{2}}{2})\\\\\)

               \(=(\frac{-2-8}{2}, \frac{-1+4}{2})\\\\=(\frac{-10}{2},\frac{3}{2})\\\\=(-5 , 1.5)\)

the binary representation of 63.25 as 111111.01.

To convert the decimal number 63.25 to binary, we need to convert the integer part (63) and the fractional part (0.25) separately.

1. Converting the integer part (63):

  Divide 63 by 2, and keep track of the remainders:

  63 ÷ 2 = 31 (remainder 1)

  31 ÷ 2 = 15 (remainder 1)

  15 ÷ 2 = 7 (remainder 1)

  7 ÷ 2 = 3 (remainder 1)

  3 ÷ 2 = 1 (remainder 1)

  1 ÷ 2 = 0 (remainder 1)

  The remainders in reverse order give us the binary representation of the integer part: 111111.

2. Converting the fractional part (0.25):

  Multiply 0.25 by 2 and record the whole number part:

  0.25 × 2 = 0.5 (0)

  0.5 × 2 = 1.0 (1)

  The whole number parts give us the binary representation of the fractional part: 01.

Putting the integer and fractional parts together, we have the binary representation of 63.25 as 111111.01.

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The binary representation of the decimal number 63.25 is 111111.01.

To convert the decimal number 63.25 to binary, we need to separate the whole number part and the fractional part.

Whole Number Part:

Divide the whole number part (63) by 2:

Divide the quotient (31) by 2:

Divide the quotient (15) by 2:

Divide the quotient (7) by 2:

Divide the quotient (3) by 2:

Divide the quotient (1) by 2:

Reading the remainders in reverse order, the binary representation of the whole number part is 111111.

Fractional Part:

To convert the fractional part (0.25) to binary, we multiply the fractional part by 2 and note the whole number part of the result. Repeat this process until the fractional part becomes 0 or until the desired precision is achieved.

Multiply the fractional part (0.25) by 2:

Multiply the fractional part (0.5) by 2:

Since the fractional part becomes 0, we stop the process.

Reading the whole number parts in order, the binary representation of the fractional part is 01.

Combining the binary representation of the whole number part and the fractional part, the binary representation of the decimal number 63.25 is 111111.01.

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Start by finding the slope of the line that passes through both the 12 roses bouquet and the 18 roses bouquet.

point 1: (12,61)

point 2: (18,79)

then, using one of the points find the fixed costs

Answer:

The general equation that represents the linear relationship is:

Answer:

90 minutes

Step-by-step explanation:

it will take twice as long therefore 90 minutes