Question

Question 19 2 pts 7. A shop owner wants to estimate the mean number of days an item stays in his store before it sold. How many items are needed to estimate the mean number of days an item stays in his store within 3 points with 95% confidence assuming s=4 based on earlier studies? O 3 O 6 O 7 O2

Answer 1

Solution :

Z_$\alpha$/2 = Z_0.025 = 1.96  

sample size = n = [Z_$\alpha$/2* $\sigma$ / E] ²

n = [1.96 *4 / 3 ]²

n = 6.82

Sample size = n = 7 items