Math 02J pre quiz

Suppose that 60% of all small business owners in a large downtown area are in favor of building a new arena. A simple random sample of 40 business owners is drawn.

a. Find the mean number of those in samples of size 40 who are in favor of the

new arena.

• 24

• 30

• 46

• 58

Suppose that 60% of all small business owners in a large downtown area are in favor of building a new arena. A simple random sample of 40 business owners is drawn.

B.- Find the standard deviation of the number of people in samples of size 40 who are in favor of the new arena. (Round your answer to two decimal places.)

• 3.098

• 3.10

• 3.85

• 3.00

The table shows the political party affiliation of each of the 67 members of the US Senate in June 2012, and when they are up for reelection.

What is the probability that a randomly selected senator is up for reelection in

November 2014? (Enter your probability as a fraction.)

• 33/67

• 25/13

• 35/68

• 25/69

A baker is deciding how many batches of muffins to make to sell in his bakery. He wants to make enough to sell to everyone and no fewer. Through observation, the baker has established a probability distribution.

What is the probability the baker will sell exactly one batch? (find P(x = 1)

x P(x)

• 0.10

• 3.3

• 0.5

• 0.85

Suppose a normal distribution has a mean of 4 and a standard deviation of 1.5. What is the z-score of x = 3.5? (Round your answer to two decimal places.)

• -0.33

• -0.22

• 0.33

• -0.68

If the area to the left of x in a normal distribution is 0.137, what is the area to the right of x? (Enter an exact number as an integer, fraction, or decimal.)

• 0.863

• 0.856

• 1.863

• 0.6841