STATS
posted by SANDRA
The top selling Red and Voss tire is rated 70,000 miles means nothing. In fact, the distance the tires can run until they wear out is a normally distributed random variable with a mean of 82,000 miles and a standard deviation of 6,400.
a. What is the probability that a tire wears out before 70,000 miles.
b. What is the probability that a tire last more than 100,000 miles?

Ms. Sue
Please use the same name for your posts. Karen, Sandra, Joi.

andrew
.6

Mariam Anwar
X~N(82000,6400^2)
a) P(X<70000)=P((X82000)/6400<(7000082000¡ Ztable=0.0303964
P(X<70000)=0.0303964
b) P(X>100000)=P(Z>2.8125)=0.0024579
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