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In: Statistics and Probability

A composition teacher wishes to see whether a new grammar program will reduce the number of...

A composition teacher wishes to see whether a new grammar program will reduce the number of grammatical errors her students make when writing a two-page essay. The data are shown here.

Student 1 2 3 4 5 6

Errors before 12 9 0 5 4 3

Errors after 9 6 1 3 2 3

a. To find the 95% confidence interval for μd., what critical value should be used?

b. Find the 95% confidence interval for μd.

Solutions

Expert Solution

First of all we need to calculate the mean and standard deviation of given data

a)

b)

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orchestra answered 2 years ago
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