# Statistics (Reiny)

posted by
**Lisa** on
.

1. A consumer organization estimates that 30% of the households in a particular community have one television set, 39% have two sets, and 20% have three or more sets. What is the probability that a household chosen at random does not have two sets?

A) 0.39

B) 0.80

C) 0.61

D) 0.20

E) 0.50

2. An Imaginary Poll in April 2005 asked 920 U.S. adults what their main source of news was: newspapers, television, internet, or radio. 681 stated that their main source of news was the internet.

Find the probability that a randomly selected U.S. adult stated that their main source of news was not the internet.

A) 0.74

B) 0.681

C) 0.50

D) 0.26

E) 0.239

3. Five multiple choice questions, each with four possible answers, appear on your history exam. What is the probability that if you just guess, you get at least one question wrong?

A) 0.20

B) 0.99902

C) 0.00098

D) 1.000

E) 0.25

4. Suppose a basketball player is an excellent free throw shooter and makes 99% of his free throws (i.e., he has a 99% chance of making a single free throw). Assume that free throw shots are independent of one another. Find the probability that the player will make three consecutive free throws.

A) 0

B) 1

C) 0.9703

D) 0.0297

5. The instructor in a Humanities class says that students have a 15% probability of making an A in her class, 20% probabilty of making a B, 25% chance of making a C, and 20% chance of making a D. The possible grades that can be assigned are A, B, C, D, and F.

What is the probability of a grade less than a C?

A) 65%

B) 20%

C) 25%

D) Cannot be determined from the information given.

E) 40% (This one?)

F) 1%