Answer
We first subtract before columns from after columns in both groups. Then we do a two-sample t-test. We can get the degrees of freedom of 13.919, the t value of 1.9136 and a p-value of 0.07647. Therefore, the evidence is not strong enough to conclude that the treatment brought about a greater improvement in math scores than the neutral message. A 90 confidence interval of the mean difference is (0.2494, 6.0506).
Work Step by Step
We first subtract before columns from after columns in both groups. Then we do a two-sample t-test. We can get the degrees of freedom of 13.919, the t value of 1.9136 and a p-value of 0.07647. Therefore, the evidence is not strong enough to conclude that the treatment brought about a greater improvement in math scores than the neutral message. A 90 confidence interval of the mean difference is (0.2494, 6.0506).
