Test bank

Chapter 11: Descriptive statistics: graphical and numerical methods

1. A researcher is interested in organizing and summarizing their sample data. To do so they will most likely employ what kinds of statistical methods?

a. Descriptive statistics

b. Experimental statistics

c. Inferential statistics

d. Bayesian statistics

2. Suppose a sample of people are asked what their favourite food is, and also their age, gender, height in centimeters and weight in kilogram are recorded. A research assistant is tasked with inputting the data. For this dataset, what column headers (from left to right) would be most appropriate?

a. name, variable 1, variable 2, variable 3, variable 4, variable 5

b. part no, favourite food, age, gender, height, weight

c. part no, food, age yrs, gender, height cm, weight kg

d. food, food, age yrs, gender, height cm, weight kg

3. You are doing a data entry check after inputting a dataset (like a prudent researcher!). Which of the following will help you quickly and efficiently check for unrealistic or invalid values?

a. Frequency tables

b. Pie charts

c. Box plots

d. Re-entering some values

4. A class of 40 students is attempting to guess the number of jellybeans in a glass jar. They write all of their numbers on a piece of paper one at a time. The last student to come up to write their number down happens to be the daughter of a statistician and remembers a “trick” to this game. Taking what value of the 39 guesses will yield a value closest to the actual value?

a. The minimum

b. The mode

c. The median

d. The standard deviation

5. The maximum length of the whiskers of a box and whisker plot are usually defined as:

a. 1.5 X IQR.

b. IQR – Q1.

c. Q3 X Q1.

d. Q3 – Q1.

6. A fundamental difference between bar plots and histograms is:

a. the order of the variables can be swapped around.

b. the bar plot shows the spread of the data.

c. the histogram shows missing data.

d. the histogram is for inspection of univariate data.

7. An experimenter is interested in the relationship between average number of hours spent watching television per week and average hours of studying per week. She gathers data from 125 students. What graphical method would be most appropriate for describing the data?

a. Histogram

b. Scatterplot

c. Bar plot

d. Box plot

8. To construct a box plot, you need to calculate what numerical information from your data?

a. The mean, median, mode, the number that splits Q1, and the number that splits Q3

b. The minimum, median, and maximum

c. The minimum, median, maximum, mean, and mode

d. The minimum, median, the number that splits Q1, the number that splits Q3, and the maximum

9. An administrative assistant collected data on average minutes spent commuting for the 16 employees in the office. The data is ranked below:

5, 8, 10, 10, 12, 15, 15, 15, 15, 15, 15, 20, 20, 20, 25, 60

What is the value of the number that splits the lowest 25% of the sample from the highest 75% of the sample (Q1)?

a. 60

b. 12

c. 5

d. 8

10. The standard deviation measures the:

a. height of the data.

b. skewness of the data.

c. central tendency of the data

d. spread of the data.

11. A marketing researcher has been tasked with identifying what brand of runners the store should carry more of. They collect data from 221 customers on shoe purchases and get the following frequency data:

Nike (104)

Addidas (13)

New Balance (41)

Asics (59)

Other (4)

What brand represents the mode of the data?

a. Nike

b. Addidas

c. Other

d. Asics

12. Bar plots are an appropriate representation of your data when your independent variable is:

a. continuous.

b. moderating.

c. categorical.

d. extraneous.

13. A researcher is interested in whether or not height is an advantage in sprint races with the hypothesis that taller people would have faster sprint times. They gather data on height measured in centimetres and time in a 100 meter sprint measured in seconds. If they want to describe this data with a graph, what would be the most appropriate plot?

a. A bar plot

b. A histogram

c. A scatterplot

d. A box plot

14. What is represented by the notation ?

a. The standard deviation

b. All of the possible values of x

c. The mean

d. The variance

15. A child has a bag of marbles containing the following types and frequencies of marbles:

Blue – 3

Red– 7

Blue and Red Striped - 18

Black – 9

If the child reaches into the bag and pulls out a marble without looing, what are the odds that the marble will be black?

a. 0.90

b. 0.33

c. 1.00

d. 0.24

16. A gardener was interested in determining how different types of fertilizer related to tomato plant fruit production. This season, he randomly assigned his 80 tomato plants to be planted with Fertilizer A, Fertilizer B, Fertilizer C, or No Fertilizer and then took frequency counts of the number of tomatoes each plant produced in the season. To get a clear picture of his data graphically he organized his data with a bar plot for group differences. What numerical representation for the bars in his chart could he use?

a. The mean tomato count

b. The median tomato count

c. The amount of fertilizer

d. Both A & B.***I’d say A and B. Median would be fine. C is part of the IV

17. A common statistic for scatterplots is the:

a. standard deviation.

b. variance.

c. mean.

d. correlation.

18. Which of the following is a potential danger of entering data incorrectly?

a. Obscuring relationships between variables

b. Revealing relationships between variables that do not exist

c. Making false inferences

d. All of these

19. The Premier League (English Football) organized data on the number of yellow-cards per club that were given over one season. The data are ranked from most to least below:

63, 63, 61, 58, 57, 56, 53, 53, 53, 53, 53, 52, 51, 51, 48, 45, 45, 42, 31, 26

What number of yellow-cards represents the median?

a. 53

b. 26

c. 63

d. 50

20. The most common way to convey information about two categorical variables is a:

a. histogram.

b. scatterplot.

c. table.

d. bar plot.