Question

Company XYZ know that replacement times for the quartz time pieces it produces are normally distributed with a mean of 15.4 years and a standard deviation of 1.4 years.

Find the probability that a randomly selected quartz time piece will have a replacement time less than 12.6 years?
P(X < 12.6 years)

If the company wants to provide a warranty so that only 3.2% of the quartz time pieces will be replaced before the warranty expires, what is the time length of the warranty?
warranty

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 120.2-cm and a standard deviation of 2.2-cm.

Find the probability that the length of a randomly selected steel rod is less than 124.8-cm.
P(X < 124.8-cm) =

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 131.5-cm and a standard deviation of 0.6-cm.
Find the probability that the length of a randomly selected steel rod is between 130.8-cm and 133.4-cm.
P(130.8-cm < X < 133.4-cm) =

Answer 1

'NoYmal 5.y 1.y) 6-15.). el 5. 0 22. Nomall 20-2 Plx 124. - 120 X- 120 2 X 2 32. X 2 z 133.4-1 3)-S