Camio Electronics Corporation makes electric diodes. It is known that the standard deviation of the lives of these diodes is 148 hours. The company's research department takes a sample of 90 such...

Camio Electronics Corporation makes electric diodes It is known that
the standard deviation of the lives of these diodes is 148 hours The
company’s research department takes a sample of 90 such diodes and
finds that the mean life of these diodes is 2255 hours What is the
probability that this sample means is:
a. not within 25 hours of the mean life of all diodes produced by this
company?
b. more than the population mean by 20 hours or more?

Extracted text: Camio Electronics Corporation makes electric diodes. It is known that the standard deviation of the lives of these diodes is 148 hours. The company's research department takes a sample of 90 such diodes and finds that the mean life of these diodes is 2255 hours. What is the probability that this sample means is: not within 25 hours of the mean life of all diodes produced by this company? a. b. more than the population mean by 20 hours or more?