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 Line Graphs, Part II Unit 11 > Lesson 1 of 10

 The graph below will be used to help us define the parts of a line graph.

Let's define the various parts of a line graph.

 title The title of the line graph tells us what the graph is about. labels The horizontal label across the bottom and the vertical label along the side tells us what kinds of facts are listed. scales The horizontal scale across the bottom and the vertical scale along the side tell us how much or how many. points The points or dots on the graph show us the facts. lines The lines connecting the points give estimates of the values between the points.

Now that we are familiar with the parts of a line graph, we can answer some questions about each of the graphs from the examples above.

 QUESTION ANSWER 1. What is the title of this line graph? Temperatures in New York City 2. What is the range of values on the horizontal scale? 1 to 6 3. What is the range of values on the vertical scale? 0 to 80 4. How many points are in the graph? 6 5. What was the lowest temperature recorded? 43° F 6. What was the highest temperature recorded? 67° F 7. At what point did the temperature dip? Day 3: 50° F

 QUESTION ANSWER 1. What is the title of this line graph? Value of Sarah's Car 2. What is the range of values on the horizontal scale? 2001 to 2007 3. What is the range of values on the vertical scale? 0 to 25,000 4. How many points are in the graph? 7 5. What was the highest value recorded? \$24,000 6. What was the lowest value recorded? \$5,800 7. Did the value of the car increase or decrease over time? decrease

 QUESTION ANSWER 1. What is the title of this line graph? Sam's Weight 2. What is the range of values on the horizontal scale? January to May 3. What is the range of values on the vertical scale? 0 to 80 4. How many points are in the graph? 5 5. What was the highest value recorded? 73 kg 6. What was the lowest value recorded? 49 kg 7. Did Sam's weight increase or decrease over time? increase

 Example 4: The line graph below shows people in a store at various times of the day.

 QUESTION ANSWER 1. What is the line graph about? People in a Store 2. What is the busiest time of day at the store? 1 pm 3. At what time does business start to slow down? 3 pm 4. How many people are in the store when it opens? 2 5. About how many people are in the store at 2:30 pm? 11 6. What was the greatest number of people in the store? 22 7. What was the least number of people in the store? 2

 Example 5: The line graph below shows the number of teens ages 13 through 19 in Smalltown that have cell phones.

 QUESTION ANSWER 1. What is the line graph about? Smalltown Teens With Cell Phones 2. At what age do teens have the greatest number cell phones? 19 years 3. At what age do teens have the least number of cell phones? 13 years 4. How many cell phones do 15 year-olds have? 341 5. About how many cell phones do 16year-olds have? 500 6. What was the greatest number of cell phones at any age? 642 7. What was the least number of cell phones at any age? 229

 Summary: A line graph is useful in displaying data or information that changes continuously over time. The points on a line graph are connected by a line. Another name for a line graph is a line chart.