An oil company is interested in estimating the true proportion of female truck d
ID: 3055413 • Letter: A
Question
An oil company is interested in estimating the true proportion of female truck drivers based in five southern states. A statistician hired by the oil company must determine the sample size needed in order to make the estimate accurate to within 1% of the true proportion with 97% confidence. What is the minimum number of truck drivers that the statistician should sample in these southern states in order to achieve the desired accuracy?
a) 11773
b) 11784
c) 11787
d) 11767
e) 11756
f) None of the above
Explanation / Answer
Solution : option a) 11773
given that p = 0.5,q = 1 - p = 0.5,E = 0.01
for 97% confidence interval,z = 2.17
n >= p*(1-p)*(z/E)^2
>= 0.5*0.5*(2.17/0.01)^2
>= 11772.25