5. A machine is set to fill the small-size packages of M&M candies with 56 candies per bag. A sample revealed three bags of 56, two bags of 57, one bag of 55, and two bags of 58. To test the hypothesis that the mean candies per bag is 56, how many degrees of freedom are there?

8

7

1

9

 6. large department store examined a sample of the 18 credit card sales and recorded the amounts charged for each of three types of credit cards: MasterCard, Visa, and Discover. Six MasterCard sales, seven Visa, and five Discover sales were recorded. The store used an ANOVA to test if the mean sales for each credit card were equal. What are the degrees of freedom for the F statistic?

3 in the numerator, 18 in the denominator

6 in the numerator, 15 in the denominator

2 in the numerator, 15 in the denominator

18 in the numerator, 3 in the denominator

7.
A random sample of 20 items is selected from a population. When computing a confidence interval for the population mean, what number of degrees of freedom should be used to determine the appropriate t-value?

19

25

20

21

9n experimental study is one that _____. 

attempts to reveal why or how one variable produces changes in another

attempts to capture a population’s characteristics by making inferences from a sample’s characteristics and testing resulting hypotheses

discovers answers to the questions who, what, when, where, or how much

involves manipulation of one or more variables to determine the effect on another variable

A random sample of size 15 is selected from a normal population. The population standard deviation is unknown. Assume the null hypothesis indicates a two-tailed test and the researcher decided to use the 0.10 significance level. For what values of t will the null hypothesis not be rejected?

To the left of -1.282 or to the right of 1.282

To the left of -1.645 or to the right of 1.645

To the left of -1.345 or to the right of 1.345

Between -1.761 and 1.761

12

Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What assumption do you need to make about the shape of the population distribution of all possible tax preparation times to make inferences about the mean time to complete a tax form?

The population distribution is skewed to the right.

The population distribution is skewed to the left.

The population distribution is normal.

The shape of the population distribution does not matter.

11

If an ANOVA test is conducted and the null hypothesis is rejected, what does this indicate?

The population means are equal.

At least one pair of population means is different.

The p-value is less than a.

All population means are different.

14Which of the following is most appropriately displayed with a frequency table?

How much explanatory value comes from the study’s variables

The home location of the most valuable customers

What percentage of people prefer Hunt’s brand ketchup

The relationship between gender and job performance

15 The monthly salaries of a sample of 100 employees were rounded to the nearest $10. They ranged from a low of $1,040 to a high of $1,720. If we want to condense the data into seven classes, what is the most convenient class interval?

$50

$200

$150

$100