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Over a 20-year period, the average grade point average of applicants to our graduate program has been found to be 3.27. This year the mean grade point average of the 37 students applying to our graduate program is 3.53, with a standard deviation of 0.29. Test the hypothesis that the current sample came from a population in which = 3.27. Use an level of 0.05 and a non-directional test.

User Teevus
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It cannot be statistically distinguished between the current sample's average GPA (3.53) and the hypothesized population average (3.27). This suggests that the observed difference might be due to chance, and we cannot confidently claim that the current applicant pool has a significantly different average GPA than the historical average.

What can be concluded after testing the hypothesis?

Hypothesis: The current sample of 37 applicants to the graduate program comes from a population with an average GPA of 3.27.

Null Hypothesis: H 0: μ = 3.27

Alternative Hypothesis: H a: μ ≠ 3.27 (non-directional)

Significance Level: α = 0.05

Test Statistic: Since we don't know the population standard deviation (σ), we'll use a one-sample t-test.

t = (x- μ) / (s / √n)

t = (3.53 - 3.27) / (0.29 / √37)

t ≈ 1.03

Using a t-distribution table with 36 degrees of freedom (n-1), we find the two-tailed p-value for t = 1.03 to be approximately 0.318.

Since the p-value (0.318) is greater than the significance level (0.05), we fail to reject the null hypothesis. This means that there is not enough evidence to conclude that the current sample comes from a population with a different average GPA than 3.27.

Based on the data, we cannot statistically distinguish between the current sample's average GPA (3.53) and the hypothesized population average (3.27). This suggests that the observed difference might be due to chance, and we cannot confidently claim that the current applicant pool has a significantly different average GPA than the historical average.

User Hakan Deryal
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