Atire company measures the tread on newly-produced tires and finds that they are normally distributed with a mean depth of 0.98mm and a standard deviation of 0.35mm. find the probability that a randomly selected tire will have a depth less than 0.70mm. would this outcome warrant a refund (meaning that it would be unusual)?

0.212 is the probability that a randomly selected tire will have a depth less than 0.70 mm.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ =  0.98 mm

Standard Deviation, σ =  0.35 mm

We are given that the distribution of tire tread is a bell shaped distribution that is a normal distribution.

Formula:

a) P(depth less than 0.70 mm)

P(x < 0.70)

Calculating from normal z table, we have:

Thus, this event is not unusual and will  not warrant a refund.