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?

6. A USA Today Poll asked a random sample of 1200 American adults what

they do with the milk in the bowl after they have eaten the cereal. 72.5%

said the drink it.

a. Describe the sampling distribution of , the proportion of American

adults who drink their milk after they have eaten their cereal.

b. Will it be unusual for fewer than 70.8% of American adults to drink their

milk after eating their cereal?

c. What is the probability that 880 or more of adult Americans drink their

milk after eating their cereal?