4.91 Suppose the students at the University of Amsterdam, the Netherlands, are classified according their school grades (X), and the number of daily hours spent watching shows on Netflix (Y = 0 for no hours, 1 for one hour, 2 for more than one hour). The joint probabilities in the accompanying table were estimated for these random variables.

Hours Spent on Netflix (Y)

Students’ Grades (X)

1 2 3 4 0 0.06 0.04 0.02 0.00 1 0.14 0.12 0.18 0.20 2 0.04 0.04 0.09 0.10

a. Find the probability that a randomly chosen student does not watch Netflix.

b. Find the means of the random variables X and Y.

c. Find and interpret the covariance between the random variables X and Y.