Question

You wish to test the following claim (Ha) at a significance level of a = 0.001. For the context of this problem, Hd = 42 Hy where the first data set represents a pre-test and the second data set represents a post-test. H:d=0 H:Hd < 0 You believe the population of difference scores is normally distributed, but you do not know the standard deviation. You obtain pre-test and post-test samples for n = 21 subjects. The average difference (post- 4.2 with a standard deviation of the differences of 8d – 6.4. pre) is d What is the test statistic for this sample? (Report answer accurate to three decimal places.) test statistics What is the p-value for this sample? (Report answer accurate to four decimal places.) p-value - The p-value is... less than (or equal to) a Ogreater than a This test statistic leads to a decision to... O reject the null accept the null O fail to reject the null

Answer 1

Test statistic,
t = (xbar - mu)/(s/sqrt(n))
t = (-4.2 - 0)/(6.4/sqrt(21))
t = -3.007

P-value Approach
P-value = 0.0035

As P-value is greater than alpha

, fail to reject null hypothesis.

There is not sufficient evidence to warrant the rejection of the claim that mean difference of post test from pre test is less than 0