Solution :
Given that,
Population standard deviation =
= 16
Margin of error = E = 5
At 90% confidence level the z is ,
= 1 - 90% = 1 - 0.90 = 0.10
/ 2 = 0.10 / 2 = 0.05
Z/2
= Z0.05 = 1.645
sample size = n = (Z/2*
/ E) 2
n = (1.645 * 16/ 5)2
n = 27.7097
n = 28
Sample size = 28
A traveler wants to estimate the difference in the mean nightly cost at Marriott and Wyndham...