Question

In: Statistics and Probability

Students in an introductory economics course were assigned to practical classes taught by various assistant teachers....

Students in an introductory economics course were assigned to practical classes taught by various assistant teachers. The 21 students in the class of one of the assistant teachers obtained an average score of 59.6 in the final exam and a standard deviation of 5.0. The 18 of the second obtained an average score in the final exam of 85.2 and a standard deviation of 13.1. Suppose these data can be considered independent random samples from populations that follow a normal distribution and have a common variance. Find the confidence interval at 80 percent of the difference between the population means. Select one:
a. The confidence interval is (-29.5575, -21.6425).
b. The confidence interval is (-29.6282, -21.5718). c. The confidence interval is (-28.6870, -22.5130).
d. The confidence interval is (-26.3103, -24.8897). and.
e The confidence interval is (-34.8609, -16.3391).

Solutions

Expert Solution

option B is correct

The confidence interval is (-29.6282, -21.5718)

Formula:


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