Deck 21: Understanding Graphs

Question 1

Exhibit 1-4
Which of the following must be true of line D in Exhibit 1-4?

A) A decrease in P is associated with a decrease in Q.
B) An increase in P is associated with an increase in Q.
C) There is no relation between P and Q.
D) There is an inverse relationship between P and Q.
E) There is a direct relationship between P and Q.

Answer 1

There is an inverse relationship between P and Q.

Question 2

Point b in Exhibit 1-1 represents

A) x = 30,y = 60
B) x = 60,y = 30
C) x + y = 60
D) x + y = 30
E) b = 90

Answer 2

x = 30,y = 60

Question 3

Exhibit 1-2
In Exhibit 1-2,curve A has a __________ slope that is __________ at every point.

A) positive; constant
B) positive; changing
C) negative; constant
D) negative; changing
E) changing; constant

Answer 3

positive; constant

Question 4

A functional relationship exists between two variables if the value of one variable depends on the value of the other variable.

Question 5

Exhibit 1-2
In Exhibit 1-2,at y = 14,the

A) value of x is larger on curve A than on curve B
B) value of x is smaller on curve A than on curve B
C) value of x is the same on curve A as on curve B
D) slope of line A is negative
E) slope of line B is positive

Question 6

On a graph with x on the horizontal axis and y on the vertical axis,the origin is

A) the point where x = 0 and y = 0
B) any point where x = 0
C) any point where y = 0
D) where a curve intersects the vertical axis
E) where a curve intersects the horizontal axis

Question 7

Any point on a graph represents a combination of particular values of two variables.

Question 8

In Exhibit 1-1,point c represents

A) x = 30,y = 60
B) x = 60,y = 30
C) c = 90
D) x + y = 60
E) x + y = 30

Question 9

Point a in Exhibit 1-1 represents

A) the origin
B) x = 0,y = 50
C) x = 50,y = 0
D) x + y = 50
E) y = 0; no information is given about x

Question 10

If x causes y,then

A) x and y are inversely related
B) y is a dependent variable
C) other variables don't matter
D) y must,in turn,cause x
E) x and y are always in a direct relation to each other

Question 11

If a given value of x is associated with a particular value of y,

A) then x causes y
B) then y causes x
C) then x and y must be logically connected
D) there are no other variables that affect the value of y
E) there may be no causal relationship between x and y

Question 12

Exhibit 1-3
In Exhibit 1-3,for any value of x,the

A) value of y is larger on curve A than on curve B
B) value of y is smaller on curve A than on curve B
C) value of y is the same on curve A as on curve B
D) slope of line A is increasing
E) slope of line B is negative

Question 13

If the dependent variable Y is directly related to the independent variable X,this means that changes in X cause changes in Y.

Question 14

Suppose y is measured on the vertical axis,x is on the horizontal axis,and the various combinations of x and y are shown by a nonvertical straight line.Which of the following must be true?

A) There is a negative relation between x and y.
B) There is a positive relation between x and y.
C) There is a causal relation between x and y.
D) If the value of x is known,the value of y can be determined.
E) The value of y is independent of the value of x.

Question 15

Exhibit 1-4
According to the curve in Exhibit 1-4,

A) if P = $8,then Q = 8
B) if P = $10,then Q = 10
C) Q increases as P increases
D) Q decreases as P decreases
E) there is a positive relation between Q and P

Question 16

Exhibit 1-2
In Exhibit 1-2,curve B has a __________ slope that is __________ at every point.

A) positive; constant
B) positive; changing
C) negative; constant
D) negative; changing
E) changing; constant

Question 17

Exhibit 1-2
In Exhibit 1-2,at x = 10,the

A) value of y is larger on curve A than on curve B
B) value of y is smaller on curve A than on curve B
C) value of y is the same on curve A as on curve B
D) slope of line A is negative
E) slope of line B is positive

Question 18

Exhibit 1-2
In Exhibit 1-2,at y = 10,the

A) value of x is larger on curve A than on curve B
B) value of x is smaller on curve A than on curve B
C) value of x is the same on curve A as on curve B
D) slope of line A is negative
E) slope of line B is positive

Question 19

Exhibit 1-2
In Exhibit 1-2,at x = 8,the

A) value of y is larger on curve A than on curve B
B) value of y is smaller on curve A than on curve B
C) value of y is the same on curve A as on curve B
D) slope of line A is negative
E) slope of line B is positive

Question 20

Exhibit 1-2
In Exhibit 1-2,at x = 12,the

A) value of y is larger on curve A than on curve B
B) value of y is smaller on curve A than on curve B
C) value of y is the same on curve A as on curve B
D) slope of line A is negative
E) slope of line B is positive

Question 21

The numerical value of the slope of a line depends in part on the units of measurement used.

Question 22

Exhibit 1-7

Using the values in Exhibit 1-7,calculate the slope of a line graphed with x on the horizontal axis and y on the vertical axis.

A) 0.5
B) 2
C) 1.5
D) 100
E) the slope cannot be determined without additional information

Question 23

The slope of a horizontal line is

A) infinitely large
B) zero
C) positive
D) negative
E) infinitely small

Question 24

Ron weighs 150 pounds.A graph relating Ron's weight on the vertical axis to Nancy's consumption of ice cream on the horizontal axis would be

A) a horizontal line at weight = 150
B) a horizontal line at weight = 0
C) a positively sloped line with decreasing slope
D) a vertical line at weight = 150
E) the origin

Question 25

One economic application of the slope of a line is

A) measuring unlimited wants
B) behavioral analysis
C) marginal analysis
D) allocative efficiency
E) rational self-interest

Question 26

Suppose a graph with Ron's weight on the vertical axis and his consumption of ice cream on the horizontal axis indicated that for each serving of ice cream he ate,Ron would gain 3 pounds,regardless of how much ice cream he had already eaten.This graph would show a

A) horizontal line at weight = 3
B) straight line with slope = 3
C) straight line with slope = 1/2
D) straight line with slope = -3
E) straight line with slope = -1/3

Question 27

The slope of a steep upward-sloping line is a smaller value than the slope of a nearly flat upward-sloping line.

Question 28

The statement that there is a direct relation between x and y means that

A) x and y move in the same direction
B) x causes y
C) y causes x
D) either y causes x or x causes y
E) the causal connection between x and y is immediate

Question 29

A graph is a

A) lengthy,inefficient,and inconvenient way to illustrate information
B) diagram illustrating a relationship between variables
C) method of proving causation
D) tool for incorporating all major and minor variables in one illustration
E) clear way to see how the fallacy of composition works

Question 30

The slope of a line

A) can only be calculated for straight lines
B) varies at different points along a straight line
C) indicates whether or not there is a causal relationship between variables
D) is independent of the units of measurement used
E) indicates how much the vertical variable changes for a given change in the horizontal variable

Question 31

The slope of a horizontal straight line is infinity.

Question 32

Exhibit 1-6
The slope of the line in Exhibit 1-6 is

A) 0.1
B) 1
C) 10
D) -0.1
E) -10

Question 33

The statement that there is an inverse relationship between x and y means that

A) x causes y
B) y causes x
C) x and y move in opposite directions
D) either y causes x or x causes y
E) there is no causal relationship between x and y

Question 34

The slope of a vertical line is

A) infinitely large
B) zero
C) positive
D) negative
E) infinitely small

Question 35

The slope of a vertical straight line is infinity.

Question 36

The slope of a line is defined as the

A) change in the value of the variable on the vertical axis divided by the change in the value of the variable on the horizontal axis
B) value of the variable on the horizontal axis divided by the value of the intercept on the vertical axis
C) change in the value of the variable on the horizontal axis divided by the increase in the value of the variable on the vertical axis
D) value of the variable on the vertical axis divided by the value of the variable on the horizontal axis
E) change in the value of the variable on the vertical axis times the increase in the value of the variable on the horizontal axis

Question 37

On a graph,the origin represents

A) the dependent variable
B) the variable that is the primary source of causation
C) a caption or explanatory description of the symbols,colors,and measurements used on the graph
D) the point at which the values of both variables are zero
E) ancestry

Question 38

Exhibit 1-4
Along the curve in Exhibit 1-4,

A) if P = $6,then Q = 8
B) if Q = 10,then P = $4
C) the slope is equal to -1
D) Q increases as P increases
E) there is a positive relationship between Q and P

Question 39

A downward-sloping straight line has a decreasing slope.

Question 40

Exhibit 1-5
The slope of the straight line in Exhibit 1-5 is

A) greater at point a than at point b
B) the same at points a and b
C) zero because the line is straight
D) negative because an inverse relation is shown
E) positive because the line lies to the right of the y-axis

Question 41

Suppose the cost of producing copper tubing is $1 per foot.If production costs were measured on the vertical axis and quantity of copper tubing were measured on the horizontal axis,which of the following lines would have the smallest slope?

A) a line representing the quantity of tubing measured in inches
B) a line representing the quantity of tubing measured in feet
C) a line representing the quantity of tubing measured in yards
D) the 45-degree line
E) any vertical line

Question 42

The slope of a U-shaped curve is infinity at the bottom of the U.

Question 43

Exhibit 1-9
In Exhibit 1-9,the slope of the line is

A) negative for all values of x
B) positive for all values of x
C) never zero
D) first negative,then positive as x increases
E) first rising,then falling as x increases

Question 44

Most economics graphs reflect the relationship between how many economic variables?

A) three
B) two
C) four
D) thirty
E) twenty

Question 45

A curved line may have a positive slope or a negative slope,but it cannot have both positive and negative areas of slope.

Question 46

The part of a graph that is most applicable to marginal analysis is the

A) origin
B) slope
C) horizontal axis
D) dependent variable
E) inverse relation

Question 47

Exhibit 1-13
Refer to Exhibit 1-13.The reason that Line (a)would shift to the position of Line (b)is

A) a change in quantity
B) a change in price
C) a change in an assumption about the relationship between the two variables observed
D) a change from a positive relation to a negative relation
E) a change from a negative relation to a positive relation

Question 48

Exhibit 1-10
The slope of the line in Exhibit 1-10 is

A) positive and constant
B) positive and increasing
C) positive and decreasing
D) negative and increasing
E) negative and decreasing

Question 49

If slope = -2 for a line on a graph with x on the horizontal axis and y on the vertical axis,then if

A) x increases by 4,y increases by 8
B) x increases by 4,y increases by 2
C) y increases by 4,x increases by 8
D) x = 4,y = 8
E) x increases by 4,y decreases by 8

Question 50

The slope of an inverted U-shaped curve is infinity at the top of the curve.

Question 51

A U-shaped curve has a positive slope everywhere.

Question 52

If slope = 2 for a line on a graph with x on the horizontal axis and y on the vertical axis,then if

A) x decreases by 4,y decreases by 8
B) x = -4,then y = -2
C) y decreases by 4,x decreases by 8
D) x = -4,y = -8
E) x increases by 4,y decreases by 8

Question 53

Exhibit 1-8
In Exhibit 1-8,the slope of the line is

A) negative for all values of x
B) positive for all values of x
C) zero at x = 7
D) first negative,then positive as x increases
E) negative for all values of y

Question 54

A straight line tangent to a curved line at a point

A) crosses the curved line at that point
B) crosses the curved line at many points
C) has the same slope as the curved line at that point
D) is steeper than the curve at all other points
E) has a smaller slope than all other points on the curve

Question 55

A tangent line is a straight line

A) that intersects a curved line twice
B) with a slope equal to infinity
C) that touches a curved line at only one point
D) that intersects a curved line at several points
E) that runs along the vertical axis

Question 56

A line is tangent to a curve if it

A) crosses the curve at one point
B) touches the curve at one point,without crossing it
C) crosses the curve at a minimum of two points
D) never touches the curve
E) forms a right triangle with the curve

Question 57

A line on a graph will shift if

A) the independent variable changes
B) there are no changes in any variables considered in the model
C) there is a change in a variable that had previously been assumed to be constant
D) a change in the independent variable causes a change in the dependent variable
E) the independent variable and the dependent variable are unrelated

Question 58

Exhibit 1-12
Using Exhibit 1-12,calculate the slope of the curve where x equals 50.

A) 0
B) 1
C) infinite
D) -1
E) the slope cannot be determined because there is no tangent line

Question 59

Moderate exercise is better than none,but excessive exercise is harmful.What is the shape of the graph of health benefits versus hours of exercise per week if health benefits are measured on the vertical axis and exercise is measured on the horizontal axis?

A) a positively sloped straight line
B) a negatively sloped straight line
C) a vertical straight line
D) a U-shaped curve
E) a hill-shaped curve