Matched or Paired Samples (Optional) · Exercise 8

Use the following information to answer next five exercises. A study was conducted to test the effectiveness of a juggling class. Before the class started, six subjects juggled as many balls as they could at once. After the class, the same six subjects juggled as many balls as they could. The differences in the number of balls are calculated. The differences have a normal distribution. Test at the 1 percent significance level.
$$\begin{array}{ccccccc}\text{Subject}& \text{A}& \text{B}& \text{C}& \text{D}& \text{E}& \text{F}\\ \text{Before}& \text{3}& \text{4}& \text{3}& \text{2}& \text{4}& \text{5}\\ \text{After}& \text{4}& \text{5}& \text{6}& \text{4}& \text{5}& \text{7}\end{array}$$

What is the sample mean difference?

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Statistics · §10.4 Matched or Paired Samples (Optional) · Exercise 8