4. For the data below;

a. Construct a discrete probability distribution for the random variable .

b. Draw a graph for the discrete probability distribution.

c. Compute the mean of the random variable .

d. Compute the standard deviation of the random variable .

() () ()

0 70

1 75

2 30

3 11

4 8

5 6

5. The completion time (in hours) for Math 2020 test follows a uniform

probability distribution with 2 6.

a. Draw a graph for the uniform distribution.

b. What is the probability that the completion time is between 1 and 4?

c. What is the probability that the completion time is greater than 5?

d. What is the probability that the completion time is less than 2.5? Will

this be unusual?