Answer:
a. There is a positive relationship. When Katie's income increases, so too does her purchase of books.
b. The relationship is plotted in the figure above.
c. The slope equals the change in the value of the variable measured on the vertical axis, income, divided by the change in the value of the variable measured along the horizontal axis, the number of books. Between $50,000 and $70,000 of income, the number of books purchased increases from 14 to 16. Hence income increases by $20,000 and the number of books increases by 2, so the slope equals $20,000/2 = 10,000.
d. As with the previous answer, the slope equals the change in income divided by the change in books. Between $90,000 and $110,000 of income, the number of books purchased increases from 18 to 20. Hence income increases by $20,000 and the number of books increases by 2, so the slope equals $20,000/2 = 10,000.
e. The slopes in parts (c) and (d) are equal. But, they must be equal because the relationship between Katie's income and the number of books she purchases is linear. For a linear relationship, the slope is the same regardless of where it is measured.
Topic: Slope
Skill: Level 3: Using models
Section: Chapter 1 Appendix - Checkpoint 3
Status: Old
AACSB: Analytic skills
15) Graph the data in the table above in the figure. Label the axes.
a. Is the relationship between X and Y positive or negative?
b. What is the slope when X = 4?
c. What is the slope when X = 8?
Answer:
The figure labels the axes and graphs the relationship.
a. The relationship between X and Y is negative.
b. The slope equals -2.
c. The slope equals -2.
Topic: Slope
Skill: Level 2: Using definitions
Section: Chapter 1 Appendix - Checkpoint 3
Status: Old
AACSB: Analytic skills
16) In the diagram below, draw a straight line with a slope of zero.
Answer:
A horizontal line has a slope of zero. The figure above shows a horizontal line with a slope of zero.
Topic: Slope of a straight line
Skill: Level 2: Using definitions
Section: Chapter 1 Appendix - Checkpoint 3
Status: Old
AACSB: Analytic skills
17) What does the slope of the line shown in the above figure equal?
Answer: The slope equals the change in variable on the y-axis divided by the change in the variable on the x-axis, or
Topic: Slope of a straight line
Skill: Level 3: Using models
Section: Chapter 1 Appendix - Checkpoint 3
Status: Old
AACSB: Analytic skills