Introductory Statistics Homeworks

Section 3.2

In Exercises 1–4, determine whether the events are independent or dependent. Explain your reasoning.

1. Tossing a coin four times, getting four heads, and tossing it a fifth time and getting a head

2. Taking a driver’s education course and passing the driver’s license exam

3. Getting high grades and being awarded an academic scholarship

4. You are given that P1A2 = 0.35 and P1B2 = 0.25. Do you have enough information to find P1A and B2? Explain.

In Exercises 5 and 6, find the probability of the sequence of events.

5. You are shopping, and your roommate has asked you to pick up toothpaste and dental rinse. However, your roommate did not tell you which brands to get. The store has eight brands of toothpaste and five brands of dental rinse. What is the probability that you will purchase the correct brands of both products? Is this an unusual event? Explain.

6. Your sock drawer has 18 folded pairs of socks, with 8 pairs of white, 6 pairs of black, and 4 pairs of blue. What is the probability, without looking in the drawer, that you will first select and remove a black pair, then select either a blue or a white pair? Is this an unusual event? Explain.