# Sampling Distribution of Sample Mean

1. The Department of Transportation issued a report that said that the average price per gallon of regular unleaded gasoline in the United States is currently $3.85, with a standard deviation of $0.21. A random sample of 49 gasoline stations is taken and their average cost per gallon for regular unleaded gasoline is calculated.

a) What is the standard error of the mean (standard error of the estimate) for this sample?

b) What is the probability that this sample average will be between $3.80 and $3.90 per gallon?

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Prob and Stats

1. The Department of Transportation issued a report that said that the average price per gallon of regular unleaded gasoline in the United States is currently $3.85, with a standard deviation of $0.21. ...

#### Solution Summary

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