A manufacturer claims that the life span of its tires is 50.000 miles. You work

Question

A manufacturer claims that the life span of its tires is 50.000 miles. You work for a consumer protection agency and you are testing these tires. Assume the life spans of the tires are normally distributed. You select 100 tires at random and test them. The mean life span is 49, 812 miles. Assume sigma = 900. Complete parts (a through (c). Assuming the manufacturer's claim is correct, what is the probability that the mean of the sample is 49, 812 miles or less? Round to four decimal places as needed.) Using your answer from part (a), what do you think of the manufacturer's claim? The claim is because the sample mean be considered unusual since it within the range of a usual event, namely within of the mean of the sample means. Assuming the manufacturer's claim is true, would it be unusual to have an individual tire with a life span of 49, 812 miles? Why or why not? because 49, 812 within the range of a usual event, namely within of the mean for an individual tire.

Explanation / Answer

a) here std error of mean =std deviation/(n)1/2 =90

hence P(X<49812)=P(Z<(49812-50000)/90)=P(Z<-2.0889)=0.0184

b) rejected ; to ; since it is not ; namely with in 95%

C)YES; 49812 is not within ; namelt with in 95%

please provide the option given in blanks so that i can answer then properly

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