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Question : Applications An economics professor states on her


Applications An economics professor states on her syllabus that final grades will be distributed using the normal distribution. The final averages of 300 students are calculated, and she groups the data into a frequency distribution as shown in the accompanying table. The mean and the standard deviation of the final are and s = 10.

Final Averages ……………………………………………………………………………... Frequency
F: Less than 50 …………………………………………………………………………….................. 5
D: 50 up to 70 …………………………………………………………………………….................. 135
C: 70 up to 80 …………………………………………………………………………….................. 105
B: 80 up to 90 …………………………………………………………………………….................. 45
A: 90 or above …………………………………………………………………………….................. 10
Total = 300

a. Using the goodness-of-fit test for normality, state the competing hypotheses in order to determine if the normal distribution is inappropriate for making grades.
b.Calculate the value of the test statistic and the p-value.
c. At the 5% significance level, what is the conclusion to the test?