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Hypothesis Testing: Compute the statistical test using the t test and decide what to do with the null.

One of the Rocky Mountain School District Principal's claims that each of his assistant principals makes 40 calls on parents per week. Several other Principals said that this estimate is too low and that their assistant principals make even more calls.

To research the claim, a random sample of 28 assistants revealed that mean number of calls made last week was 42. The standard deviation of the sample was computed to be 21 calls. At the 0.05 level of significance can we conclude that more than 40 calls are made on the average in a week?

State the research Hypothesis and the Null Hypothesis.
Test = t test

Solution Preview

Let the mean of weekly calls made be U.
<br>H0: U=40 (not more than 40 calls are made)
<br>H1: U>40(more than 40 calls are made, then this is a one-tailed ...

Solution Summary

The solution addresses one of the Rocky Mountain School District Principal's claims that each of his assistant principals makes 40 calls on parents per week. Several other Principals said that this estimate is too low and that their assistant principals make even more calls.
To research the claim, a random sample of 28 assistants revealed that mean number of calls made last week was 42. The standard deviation of the sample was computed to be 21 calls. At the 0.05 level of significance can we conclude that more than 40 calls are made on the average in a week?

State the research Hypothesis and the Null Hypothesis.
Test = t test

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