# Normal Probability

Answer the questions about the specified normal distribution.

a. The lifetime of ZZZ batteries are normally distributed with a mean of 265 hours and a standard deviation of 10 hours. Find the number of hours that represent the the 40th percentile.

b. Scores on an English placement test are normally distributed with a mean of 36 and standard deviation of 6.5. Find the score that marks the top 5%.

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#### Solution Summary

The solution provides step-by-step method for the calculation of probability based on Z score. Formula for the calculation and Interpretations of the results are also included.

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