1.A study is conducted to study the effects of antioxidants on the body fat.Half the study participants are given an antioxidant compound, and the other half take a placebo.Body fat measurements (body fat percentages) are taken of the group after several weeks and compared.

_____1A.What is the independent variable?(1 point each)

a.antioxidants

b. body fat

c. placebo

d. none of the above

_____1B.What scale of measure is used for the dependent variable?(1 point)

a. nominal

b. ordinal

c. interval

d. ratio

_____2.In ANOVA, if MS(error) and MS group are____________ then we have support for the fact that the null is really _________.

a. the same; true

b. the same; false

c. different; true

d. none of the above

_____3.An outlier...

a.results from coding errors and should be removed from the data set

b.is any value that is far away from the bulk of values in the data set

c.is a measure of variability

d.is a measure of central tendency

_____4.What is the critical value of a two-tailed z-test with a = .01?

a.2.33

b. 2.58

c.1.64

d.1.96

_____5.If you conduct a single-sample t-test with 20 participants with = .05, two-tailed, what are your critical values?

a.+2.093

b.+2.861

c.+2.086

d.+1.729

_____6.Which of the following is an example of a nominal scale of measurement?

a. television stations

b. IQ

c. percentage correct on an exam

d. weight

_____7.Which of the following statements is true?

a.inferential statistics make inferences about sample statistics

b.descriptive statistics allow for inferences about population parameters

c.descriptive statistics describe population statistics

d.inferential statistics allow for inferences about population parameters(1 point)

8.The mean age of onset of Alzheimer's is= 72, with = 5.What proportion will develop Alzheimer's at age 65 or younger?(2 points)

9.A researcher rejects a null hypothesis at = .05.What is the probability that the researcher made a Type I error (assuming that the null is really true)?(1 point)

a. 5%c. 1%

b. 0%d. 99%

10.Use the following distribution of sample values to compute the standard deviation.

5581012

(2 points)

11. To improve employee morale, an organization lets its employees pick among three prizes: a boat, a car, and a vacation (all worth about the same).Each employee chose a prize and the resulting distribution is given below.

PrizeFrequency

Boat20

Car40

Vacation20

11A.If one employee was chosen at random, what is the probability that the employee chose the boat?Put your answer in decimal form.

_____________(1 point)

11B.If one employee was chosen at random, what is the probability that the employee chose the boat or the car? Put your answer in decimal form.

_____________(1 point