Question

The diameter of an electric cable is normally distributed, with a mean of 0.8 inch and a standard deviation of 0.01 inch. What is the probability that the diameter will exceed 0.82 inch? (Give the answer to four decimal places.)

Answer 1

0.82 - 0.8 = 0.02

0.02/0.01 = 2 standard deviations

You check a normal distribution table (unless you were provided with the value for 2 standard deviation already)

You get : Greater than 2 standard deviation = 1 - 0.9772 = 0.0228

Answer 2

The diameter of an electric cable is normally distributed, with a mean of 0.8 inch and a standard deviation of 0.01 inch. What is the probability that the diameter will exceed 0.81 inch