Suppose you conducted a study and obtain subjects' weight at beginning of the study (pre) and provide intervention and collect weight again (post). There are no missing data.

Estimate for the common variance of an outcome at either of the two timepoints is 100.

Correlation among outcomes form same subject esimated to be 0.8.

Sample mean (Pre) = 100

Sample Mean (post) = 105

N = 100

You can use critical values from standard normal distributoin for t-test.

State whether you reject or fail to reject the null hypothesis of equal means and explain how you came to that conclusion.