Answer to Question #198242 in Statistics and Probability for Janine Sharp

Question

Suppose that the time required to complete a 1040R tax form is normally distributed with a mean of 100 minutes and a standard deviation of 20 minutes. What proportion of 1040R tax forms will be completed in more than 127 minutes? Round your answer to at least four decimal places.

Answer 1

$\mu=100,\sigma=20$

Proportion of 1040R tax forms will be completed in more than 127 minutes-

$P(X>127)=P(z>\dfrac{127-100}{20})=P(z>\dfrac{27}{20})=P(z>1.35)=0.0885$

Hence The proportion is 8.85%.