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## In the morning class, the mean on the first exam was 78 with a standard deviation of 2.3 for

In the morning class, the mean on the first exam was 78 with a standard deviation of 2.3 for

the 57 students in the class. In the afternoon class, the mean was 81 with a standard deviation

of 5.7 for the 37 students in the class. Determine the 90% confidence interval for the

difference in the means of the two groups

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