AP Statistics Unit 8

The manager of a high school cafeteria is planning to offer several new types of food for student lunches in the following school year. She wants to know if each type of food will be equally popular so she can start ordering supplies and making other plans. To find out, she selects a random sample of 100 students and asks them, "Which type of food do you prefer: Asian food, Mexican food, pizza, or hamburgers?" The table shows the data. The chi-square statistic is

Which of the following is the central limit theorem used for?

• The standard deviation of the distribution of sample means is found by dividing the population standard deviation by n.

• The distribution of sample means will be approximately normal if the sample size is at least 30.

• The distribution of sample proportions is approximately normal if both np and n(1 - p) are greater than or equal to 10.

• As sample size increases, variability decreases.

A company has 500 employees and wants to evaluate a proportion using the distribution of sample proportions and normal curve. Under which circumstance will they be able to do this?

• n = 80, p = .2

• n = 40, p = .2

• n = 40, p = .9

• n = 30, p = .4

The average points scored in an NBA game is 220 with a standard deviation of 18. Determine the likelihood that a random sample of 40 games would have a mean less than 225.

• Cannot be determined

• 0.9605

• 0.6094

• 0.8563

10% of people are left handed. If 800 people are randomly selected, find the likelihood that at least 12% of the sample is left handed.

• 0.0297

• 0.0106

• 0.0409

• 0.0816

10% of people are left handed. Of the following, what is the smallest sample size needed to be at least 90% sure that the sample proportion will be between 9% and 11%?

• 1500

• 2000

• 2500

• 3000

A specific brand of potato chips sells bags such that the weights are N(8,0.5). If the probability that a sample of n bags has an average weight over 8.2 ounces is 0.0548, what sample size was used?

• 4

• 16

• 36

• 64

53.2% of applicants are accepted into UConn. In a sample of 100 UConn applicants, 45 of them were accepted. What is the parameter?

• All UConn applicants.

• The 100 applicants in the sample.

• 53.2% acceptance rate.

• 45% of accepted in sample.

The average points scored in an NBA game is 220 with a standard deviation of 18. Determine the likelihood that a sample of 10 games would have a mean greater than 230.

• 0.0395

• 0.0817

• 0.2893

• Cannot be determined

• A

• B

• C

• D

• E