SOLUTION: The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 1800 miles. What i

Algebra.Com
Question 1160736: The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 1800 miles. What is the probability a certain tire of this brand will last between 56,220 miles and 56,760 miles?
0.4920
0.4649
0.9813
0.0180

Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
z=(x-mean)/sd
this is between -3780/1800 or -2.1
and -3240/1800 or -1.8
That probability of z between those two values is 0.01807
last choice Is the best.

RELATED QUESTIONS

The tread life of a particular brand of tire is a random variable best described by a... (answered by Boreal)
The tread life of a particular brand of tire is a random variable best described by a... (answered by stanbon)
The tread life of a particular brand of tire can be describe by a normal distribution... (answered by Boreal)
A tire manufacturer believes the tread life of snow tires has a normal distribution with... (answered by stanbon)
The U.S. Department of Transportation requires tire manufacturers to provide tire... (answered by stanbon)
A shipping firm suspects that the mean life of a certain brand of tire used by its trucks (answered by Boreal)
A new life-long tire has a tread depth of 7/16 inches, instead of the more typical 13/32... (answered by Alan3354)
1. A tire manufacturer wishes to investigate the tread life of its tires. A sample of 10... (answered by CPhill)
A new tire has a tread of about .34 inch. After 5000 miles the tread is about .31 inch.... (answered by richwmiller)