# MGMT 650 MGMT650 Quiz 2 Answers (UMUC)

MGMT 650 Quiz 2 (UMUC)

- The proportion of adult women in a certain geographical region is approximately 52%. A marketing survey telephones 300 people at random. Complete parts a and b below.
- Data from a small bookstore are shown in the accompanying table. Complete parts a through
- In many state lotteries you can choose which numbers to play. Consider a common fonn in which you choose 5 numbers. Which of the following strategies can improve your chance of winning? If the method works, explain why. If not, explain why using appropriate statistics terms.
- In many state lotteries you can choose which numbers to play. Consider a common fonn in which you choose 5 numbers. Which of the following strategies can improve your chance of winning? If the method works, explain why. If not, explain why using appropriate statistics terms.

a) Choose randomly from among the numbers that have not come up in the last 3 lottery drawings.

b) Choose the numbers that did come up in the most recent lottery drawing.

5. A ceramics factory can fire eight large batches ofpottery a day. In order to better understand pieces breaking, the factory records the number of broken pieces in each batch for 3 days and then creates the scatterplot shown to the right.

6. A consumer organization estimates that over a !-year period 20% of cars will need to be repaired once, 8% will need repairs twice, and 1% will require three or more repairs. What is the probability that a car chosen at random will need

a) no repairs?

b) no more than one repair?

c) some repairs?

7.Assume that the conditions for correlation are met. Is the following statement true or false? If it is false, explain.

A correlation of - 0.95 indicates a strong, negative association.

8. An investment website can tell what devices are used to access the site. The site managers wonder whether they should enhance the facilities for trading via "smart phones," so they want to estimate the proportion of users who access the site that way (even if they also use their computers sometimes). They draw a random sample of200 investors from their customers. Suppose that the true proportion of smart phone users is 41%. Complete parts a through c below.