How many pairs of points are reflections across the x-axis?
A)1
B)2
C)3
D)4

Calculate the mean value (expected value) of the following discrete variable x (10 points): x = 0, 1, 2, 3, 4, 5, 6 p(x) = 0.2, 0.2, 0.15, 0.15, 0.15, 0.1, 0.05