# Hypothesis testing - Confidence Intervals

Problem. Test scores for class are: 93%, 77%, 90%, 85%, 86%, 81%, 88%

At a = .10 can it be said that the standard deviation is greater than 4%. State (1) the null hypothesis (2) determine the critical value (3) determine the test statistic (4) State decision and summary

Also, construct the 90% confidence interval for the population standard deviation

Please show work and formulas.

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#### Solution Summary

The solution calculates the confidence intervals for test scores for class.

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