Question

A company advertises two car tire models. The number of thousands of miles that the standard model tires last has a mean μ S​ =60 and standard deviation σ S​ =5. The number of miles that the extended life tires last has a mean μ E​ =70 and standard deviation σ E​ =7. If mileages for both tires follow a normal distribution, what is the probability that a randomly selected standard model tire will get more mileage than a randomly selected extended life tire?

Answer 1

Answer: .123

Step-by-step explanation: use random variable e-s which will follow a normal distribution with a mean of 70-60=10 and SD= sq root of 25+49. P(e-s<0)=.123