Question

Test the claim that for the population of statistics final exams, the mean score is 70 using alternative hypothesis that the mean score is different from 70. Sample statistics include n=20,x¯=71, and s=15. Use a significance level of α=0.05. (Assume normally distributed population.)

The test statistic is
The positive critical value is
The negative critical value is
The conclusion is

A. There is sufficient evidence to reject the claim that the mean score is equal to 70.
B. There is not sufficient evidence to reject the claim that the mean score is equal to 70.

Answer 1

Claim is that mean = 70

test statistic calculation

degree of freedom = n-1 = 20-1 = 19 and alpha level = 0.05

t critical = T.INV.2T(alpha,df) = T.INV.2T(0.05, 19) = -2.093 and 2.093

positive critical value is 2.093 and negative critical value is -2.093

Here, -2.093 < test statistic < 2.093, failing to reject the null hypothesis

Conclusion:-

B. There is not sufficient evidence to reject the claim that the mean score is equal to 70.