A reproductive clinic had a success rate of 25% of patients with live births in 2008. They want to update their success rate (the proportion of live births) for 2020. If they want their estimate to be within 2.5%, how many patient's results should they sample if they plan to use a 99% confidence interval? Round your answer up to the nearest integer.

They should sample the results of 1990 patient results.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.

In which

z is the z-score that has a p-value of .

The margin of error is of:

A reproductive clinic had a success rate of 25% of patients with live births in 2008.

This means that

99% confidence level

So , z is the value of Z that has a p-value of , so .

If they want their estimate to be within 2.5%, how many patient's results should they sample if they plan to use a 99% confidence interval?

They should sample n patients.

n is found for . So

Rounding up:

They should sample the results of 1990 patient results.

1,918

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional