A university system enrolling thousands of students needs to determine how many credit hours, on the...

A university system enrolling thousands of students needs to determine how many credit hours, on the average, each student takes per quarter. From previous studies, the population standard deviation is known to be 2.3 credit hours per quarter. Suppose the administration wanted to estimate the mean to within 0.1 hours with 95% confidence. How large a sample would they need to take?

Expert Solution

Solution

standard deviation = =2.3

Margin of error = E = 0.1

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96

sample size = n = [Z/2* / E] 2

n = ( 1.96*2.3 /0.1 )2

n =2032.20

Sample size = n =2033

orchestra answered 2 years ago

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