STAT 1350, Quiz #5, Summer 2014 Name _______________________________________

1. A company database contains the following information about each employee: age, date hired, sex (male or female), ethnic group (Asian, black, Hispanic, etc.), job category (clerical, management, technical, etc.), and yearly salary. Which of the following lists of variables are all categorical?
A) Age, sex, ethnic group
B) Sex, ethnic group, job category
C) Ethnic group, job category, yearly salary
D) Yearly salary, age
E) Age, date hired
Ans: B

2. You have data on returns on common stocks for all years since 1945. To show clearly how returns have changed over time, your best choice of graph is a
A) bar graph. D) histogram.
B) line graph. E) scatterplot.
C) pie chart.
Ans: B

3. A bar graph compares the size of the armed forces for China, North Korea, Russia, and the United States. To make the graph look nicer, the artist replaces each bar by a proportionally correct picture of a soldier that is enlarged or reduced to be as tall as the bar. This graph is misleading because
A) it’s the wrong kind of graph. Use a pie chart instead.
B) it’s the wrong kind of graph. Use a scatterplot instead.
C) China’s armed forces are twice as large as those of North Korea, but the choice of vertical scale can change this to half as large or four times as large.
D) China’s armed forces are twice as large as those of North Korea, but the area of China’s soldier picture is four times as large as the North Korea picture.
Ans: D

4. A common abuse of bar graphs is to
A) use bars of equal width so that we can\'t see differences among the bars.
B) replace bars by pictures and increase both height and width as the variable plotted increases.
C) use bars that don’t touch each other.
D) draw the bars vertically rather than horizontally.
E) stretch or squeeze the scale at the base of the bars so that our eyes are misled.
Ans: B

5. You measure the age, marital status, smoking status (smoker or nonsmoker), and earned income of a simple random sample of 1463 women. The number of variables you have measured is
A) 1463—the size of the sample.
B) five—age, marital status, smoking status, income, and number of women.
C) four—age, marital status, smoking status, and income.
D) two—age and income. Marital status and smoking status are not variables because they don’t have units like years or dollars.
Ans: C

6. A line graph shows that the price of fresh oranges falls early in each year when the orange harvest in Florida is ready, then it rises late in the year when oranges from that year’s harvest begin to run out. This is an example of
A) trend in a line graph.
B) erratic fluctuations in a line graph.
C) seasonal variation in a line graph.
D) confounding.
Ans: C

7. In order to create a good graph, you must do each of the following EXCEPT
A) clearly label the axes or provide a legend.
B) use three-dimensional effects, many colors, and eye-catching backgrounds.
C) avoid pictograms.
D) make the data stand out.
Ans: B

8. A __________ tells us what values a variable takes and how often it takes those values.
A) distribution B) quantity C) seasonal variation D) trend
Ans: A

9. The proper graph for showing distribution of students at this university is a
A) line graph. B) stemplot. C) histogram. D) pie chart.
Ans: D