Question

A bearing is selected a random and measured. The radius of ball bearings

produced by a particular process follow a normal distribution with y =

0.255 and g=0.001 inches. What is the probability that the radius is at

most 0.2545 in?

Answer 1

$$P(X\le0.2545)=P(Z\le\dfrac{0.2545-0.255}{0.001})$$

$$=P(Z\le -0.5)\approx0.3085$$