# Probability : Confidence Interval

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After reviewing 100 drug stores across nation, you discover that a certain prescription drug has an average price of $40 for $20 pills with a standard deviation of $5. Using this information, deduce with 95% accuracy where the national average cost of 20 pills lies.

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#### Solution Preview

average = 40

n = 100

deviation = 5

alpha = 0.05

z(alpha/2) = ...

#### Solution Summary

A confidence interval is investigated. The response received a rating of "5" from the student who originally posted the question.

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