Costco installs automobile tires on a first-come first-serve basis. the total time a customer needs to wait for the installation to be completed follows the normal distribution with a mean time of 106.3 minutes and a standard deviation of 18.5 minutes. what is the probability that a randomly selected customer will wait between 80 and 95 minutes for his or her tires to be installed?
Given: μ=106.3 minutes σ=18.5 minutes Need to find P(80<x<95)=> P(x)=Z((95-μ)/σ)-Z((80-μ)/σ) =Z(-0.61081)-Z(-1.42162) =0.27066-0.077568 =0.1931 Therefore probability of customers waiting between 80 and 95 minutes is 0.1931
