Holt CA Course 1

7-8 Interpreting Graphs

AF1.5 Represent quantitative relationships graphically and interpret the meaning of a specific part of a graph in the situation represented by the graph.

California Standards

Holt CA Course 1

7-8 Interpreting Graphs

The graph shows the varying speeds at which Emma exercises her horse. • The horse walks at a

constant speed for the first 10 minutes.

• Its speed increases over the next 7 minutes.

• It gallops at a constant rate for 20 minutes.

• Then it slows down over the next 3 minutes.• It walks at a constant pace for 10 minutes.

Holt CA Course 1

7-8 Interpreting Graphs

The height of a tree increases over time, but not at a constant rate. Which graph bests shows this?

Additional Example 1: Relating Graphs to Situations

As the tree grows, its height increases and then reaches its maximum height. Graph A shows the height of a tree remaining at a constant rate without reaching a maximum height. The answer is graph B.

A. B.

Holt CA Course 1

7-8 Interpreting GraphsCheck It Out! Example 1

The dimensions of the basketball court have changed over the years. However, the height of the basket has not changed. Which graph bests shows this?

Graph A shows the height of the basket remaining constant. Graph B shows the height increasing without reaching a maximum height. The answer is graph A.

A. B.

Holt CA Course 1

7-8 Interpreting Graphs

Additional Example 2: Sketching Graphs for Situations

Jarod parked his car in the supermarket parking lot and walked 40 ft into the store and to the customer service counter, where he waited in line to pay his electric bill. Jarod then walked 60 ft to the back of the store to get 2 gallons of milk and walked 50 ft to the checkout near the front of the store to pay for them. After waiting his turn and paying for the milk, he walked back 50 ft to his car. Sketch a graph to show Jarod’s distance from his car over time.

Holt CA Course 1

7-8 Interpreting Graphs

Additional Example 2 Continued

Step 1: List the different actions you need to show on the graph. The describe the segment for each action.

● Jarod walks inside the store.

● Jarod waits in line.

● Walks to the back of store

Distance from parking lot increases: segment slants upward.

Distance does not change: horizontal segment.

Distance from parking lot increases: segment slants upward.

Holt CA Course 1

7-8 Interpreting Graphs

Additional Example 2 Continued

Step 1: List the different actions you need to show on the graph. The describe the segment for each action.

● Walks to the front of the store

● Waits in line.

● Returns to car.

Distance from parking lot decreases: segment slants downward.

Distance does not change: horizontal segment.

Distance from parking lot decreases: segment slants downward.

Holt CA Course 1

7-8 Interpreting GraphsAdditional Example 2 Continued

Step 2: Draw the graph.

Time

Dis

tance

fro

m c

ar

(ft)

0

20

40

60

80

100

120

walks inside

waits in line

walks to back

walks to front

waits in line

back to car

Holt CA Course 1

7-8 Interpreting Graphs

Check It Out! Example 2

Darcy traveled 22 miles from her house to the Peterman’s house were she babysat for 1 hour. After babysitting she traveled 8 miles further to the deli to buy a sandwich. After eating her sandwich she returned home. Sketch a graph to show Darcy’s distance from her house over time.

Holt CA Course 1

7-8 Interpreting Graphs

Check It Out! Example 2 Continued Step 1: List the different actions you need to show on the graph. The describe the segment for each action.

● Darcy travels from her house to the Peterman’s house.

● She baby sits for 1 hour.

● After babysitting she travels to the deli

● She eats a sandwich

● She returns home

Distance from home increases: segment slants upward.

Distance does not change: horizontal segment.

Distance from home increases: segment slants upward.

Distance does not change: horizontal segment.

Distance from home decreases: segment slants downward.

Holt CA Course 1

7-8 Interpreting Graphs

Check It Out! Example 2 Continued

Step 2: Draw a graph

Time

Dis

tance

fro

m h

ou

se

0

5

10

20

30

40

50

Drives away from her house

baby sits

drives to delieats

drives home