SOLUTION: 1. A tire company finds the lifespan for one brand of its tires is normally distributed with a mean of 49,900 miles and a standard deviation of 6000 miles. If the manufacturer is w

Algebra ->  Statistics  -> Normal-probability -> SOLUTION: 1. A tire company finds the lifespan for one brand of its tires is normally distributed with a mean of 49,900 miles and a standard deviation of 6000 miles. If the manufacturer is w      Log On


   

Question 930002: 1. A tire company finds the lifespan for one brand of its tires is normally distributed with a mean of 49,900 miles and a standard deviation of 6000 miles. If the manufacturer is willing to replace less than 10% of the tires, what should be the approximate number of miles for a warranty?
59,770
42,220
40,030
None of the above
57,580
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
6000(invNorm(.90)) + 49,900 = 6000(1.28) + 49,900 = 57,580
top 10% of the tires have more than 57,580mi