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Random Selection and Normal Distribution

The diameter of a Ping-Pong ball manufactured at a factory is expected to be approximately normally distributed with a mean of 1.30 inches and a standard deviation of 0.04 inch. What is the probability that a randomly selected Ping-Pong ball will have a diameter between 1.31 and 1.33 inches?

A. 0.0987
B. 0.1747
C. 0.2734
D. 0.3721

Solution Preview

The correct answer is B.

This question can be easily solved using a calculator (I will explain below how to do it with the standard normal table instead of a calculator).

I use the online calculator at
Enter 1.30 as the mean and 0.04 as the std dev. Then choose to calculate the area ...

Solution Summary

This solution provides step by step equations and explanations for a problem involving normal distribution and random selection.