Question 907:
1Answer:
No answer provided yet.We will use a 1-sample t-test here to test the hypothesis that the population mean is equal to 50.The test statistic is found as the difference between the sample and test mean (which is 49-50) divided by the standard error of the mean (SEM). The SEM is the standard deviation divided by the square root of the sample size : 3/SQRT(20) = .671
So the test statistic is -1/.671 = -1.49
To find the significance of this test statistic we need to use a t-table or use the Excel function = TDIST(1.49,19, 2) where the parameters are the test statistic, the degrees of freedom (20-1) and 2 tails for a 2-sided test of significance.
We get a 2-tailed p-value of .1524 which is GREATER than the alpha value of .05. We then fail to reject the null hypothesis. We conclude that the population mean is equal to 50.