Question

A state wildlife service wants to estimate the mean number of days that each licensed hunter actual hunts during a given season, with a margin of error estimation equal to 2 hunting days. If data collected in earlier surveys have shown σ to be approximately equal to 10, how many hunters must be included in the survey with a 90% confidence interval?

Answer 1

Solution :

Given that,

standard deviation =   =10

Margin of error = E = 2

At 90% confidence level

= 1 - 90%  

= 1 - 0.90 =0.10

/2 = 0.05

Z/2 = Z0.05 = 1.645

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

n = ( 1.645 * 10/ 2)2

n =67.65

Sample size = n =68