You can play around with Z table stuff at
davidmlane.com/hyperstat/z_table.html
The top-selling Amar tire is rated 70,000 KMs, which 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 KMs and a standard deviation of 6,400 KMs.
What is the probability that a tire wears out before 70,000 KMs? What is the probability that a tire lasts more than 100,000 KMs?
Note: You may use Z-table for this
1 answer