In a survey of zoom animals, for out of five monkeys preferred very ripe.What is this result as a percent?

A selective college would like to have an entering class of 950 students. Because not all students who are offered admission acc

pogonyaev

Answer:

a) The mean is 900 and the standard deviation is 15.

b) 100% probability that at least 800 students accept.

c) 0.05% probability that more than 950 will accept.

d) 94.84% probability that more than 950 will accept

Step-by-step explanation:

We use the normal approximation to the binomial to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

(a) What are the mean and the standard deviation of the number X of students who accept?

$n = 1200, p = 0.75$ . So

$E(X) = np = 1200*0.75 = 900$

$\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{1200*0.75*0.25} = 15$

The mean is 900 and the standard deviation is 15.

(b) Use the Normal approximation to find the probability that at least 800 students accept.

Using continuity corrections, this is $P(X \geq 800 - 0.5) = P(X \geq 799.5)$ , which is 1 subtracted by the pvalue of Z when X = 799.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{799.5 - 900}{15}$

$Z = -6.7$

$Z = -6.7$ has a pvalue of 0.

1 - 0 = 1

100% probability that at least 800 students accept.

(c) The college does not want more than 950 students. What is the probability that more than 950 will accept?

Using continuity corrections, this is $P(X \geq 950 - 0.5) = P(X \geq 949.5)$ , which is 1 subtracted by the pvalue of Z when X = 949.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{949.5 - 900}{15}$

$Z = 3.3$

$Z = 3.3$ has a pvalue of 0.9995

1 - 0.9995 = 0.0005

0.05% probability that more than 950 will accept.

(d) If the college decides to increase the number of admission offers to 1300, what is the probability that more than 950 will accept?

Now n = 1300. So

$E(X) = np = 1300*0.75 = 975$

$\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{1200*0.75*0.25} = 15.6$

Same logic as c.

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{949.5 - 975}{15.6}$

$Z = -1.63$

$Z = -1.63$ has a pvalue of 0.0516

1 - 0.0516 = 0.9484

94.84% probability that more than 950 will accept

5 0

2 years ago

Find the distance between the points (0,-8) and (3,2). Round your answer to the nearest hundredth.

Reil [10]

Answer:

10.44

Step-by-step explanation:

First plot each of the points on to a graph at their respective positions.

Following that create a 90° triangle out of the points. This will create a 3 by 10 triangle. (3 to 0 is 3) (-8 to 2 is a difference of 10)

You can then use the pythagorean theorem $a^{2} +b^{2} = c^{2}$ .

Insert the lengths of each of the sides that we got earlier which would be 3 and 10 into the equation. $3^{2} + 10^{2} = c^{2}$

Since we want to find the hypotenuse which is equal to c we work the equation to 9+100 = $c^{2}$ which in turn is 109 = $c^{2}$

Then take the square root of 109 to remove the square from the c to get c = 10.44

6 0

3 years ago

Which facts are true for the graph of the function below? Check all that apply. F(x) = 4 5x

RoseWind [281]

The answers are E.) y-int is (0,4), F.) domain of F(x) is all rel numbers , and C.) it is increasing

3 0

2 years ago

Read 2 more answers

What property describe the number sentence 6 plus 0 equal 6

nata0808 [166]

The identity property of addition states that any number plus zero equals the original number. So, 6 + 0 = 6 shows the identity property of addition. Other number sentences that show this property would include: 8 + 0 = 8, 153 + 0 = 153, and 1,899,888 + 0 = 1,899,888. In each case, the original number plus 0 equals the original number. It doesn't matter how large or small the original number is.

8 0

3 years ago

In a room with 10 people, how many different handshakes are possible?

Ganezh [65]

45 handshakes are possible

7 0

3 years ago

Read 2 more answers