Amechanic sells a brand of automobile tire that has a life expectancy that is normally distributed, with a mean life of 34 , 000 miles and a standard deviation of 2500 miles. he wants to give a guarantee for free replacement of tires that don't wear well. how should he word his guarantee if he is willing to replace approximately 10% of the tires?

He should word his statement as "Free replacement for tires that wear before 30875 miles."

Step-by-step explanation:

If he is willing to replace 10% of tires he should find the life of tires that gives an area of 10% in the normal distribution graph.

Now for 10% of area standard normal deviate Z can be obtained from normal distribution table

Using normal distribution table for 10% area we have Z = -1.28

Thus we have

Applying given values we get

answer: 7 x 2/5 = 2.8 hours, is your answer. your welcome! : 3

step-by-step explanation: first work out how long it took to hose 1/7 of the lawn which is 2/5 hours. times that by 7 to get the whole lawn.

sorry i don't know the other answer. i didn't learn what a proportional relationship is.

what? that isnt a question

step-by-step explanation: