In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

At 95% confidence, how large a sample should be taken to obtain a margin of error of 0.03 for the estimation of a population proportion?

We need a sample of n.

n is found when M = 0.03.

We have no prior estimate of $\pi$ , so we use the worst case scenario, which is $\pi = 0.5$

Then

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.03 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.03\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.03}$

$(\sqrt{n})^{2} = (\frac{1.96*0.5}{0.03})^{2}$

$n = 1067.11$

Rounding up

A sample of 1068 is needed.

8 0

3 years ago

Consider an experiment with a deck of 52 playing cards, in which there are 13 cards in each suit, two suits are black, and two s

lakkis [162]

Answer:

P (E1) = 1/2 or 50%

P (E2) = 3/13 or 23%

Step-by-step explanation:

1. Let's review the information given to us to answer the question correctly:

Number of playing cards = 52

Number of suits = 4

Number of cards per suit = 13

Number of black suits = 2

Number of red suits = 2

2. Suppose E1 = the outcome is a red card and E2 = the outcome is a face card (K, Q, J). Determine P(E1 or E2).

P (E1) = Number of red cards/Total of playing cards

P (E1) = 26/52 = 1/2 = 50%

P (E2) = Number of face cards/Total of playing cards

P (E2) = 12/52 = 3/13 = 23%

8 0

3 years ago

Read 3 more answers

I’ll give the Brainliest!!!

Varvara68 [4.7K]

It’s B hope this helps

7 0

3 years ago

What is the average rate of change for ƒ(x) = −2x + 70 over the interval 2 ≤ x ≤ 6?

Anvisha [2.4K]

Answer:

The average rate of change is -2

Step-by-step explanation:

we know that

To find out the average rate of change, we divide the change in the output value by the change in the input value.

In a linear function the average rate of change is a constant and is equal to the slope of the function

The linear function in slope intercept form is equal to

$f(x)=mx+b$

where

m is the slope or unit rate of the linear function

b is the y-intercept or initial value of the linear function

In this problem we have

$f(x)=-2x+70$

$m=-2\\b=70$

therefore

The average rate of change is -2

4 0

3 years ago