Line Plots — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. A Grade 3 line plot has 5 Xs above 2 and 3 Xs above 4. There are 2 more students with 2 than 4.
To find how many more, subtract: 5 minus 3 equals 2, so 2 more students chose 2 than chose 4.
2. A Grade 3 line plot shows 2, 4, 3, and 1 Xs above values 1, 2, 3, and 4. The total surveyed is 10.
Total students surveyed equals the sum of all Xs: 2 plus 4 plus 3 plus 1 equals 10 students.
3. If the tallest stack on a Grade 3 line plot is above 3 books, the mode is 3 books.
The mode is the value with the tallest stack of Xs, so a tallest stack above 3 makes the mode 3 books.
4. A Grade 3 line plot has 6 Xs total and 4 are above 0 pets. Then 2 Xs are above other values.
Total Xs minus Xs at one value equals Xs at the rest: 6 minus 4 equals 2 Xs above other values.
5. A Grade 3 line plot shows 1 X above 0, 3 Xs above 1, and 2 Xs above 2. The least common value is 0.
The least common value has the shortest stack of Xs, and 1 X is the smallest count, so 0 is least common.
6. On a Grade 3 line plot, 4 students had 2 books and 4 students had 5 books. So 2 and 5 are equally common.
When two values share the same number of Xs, they are equally common because their stacks have the same height.
7. A Grade 3 line plot has 7 Xs. After 3 more students answer, the new total is 10 Xs.
Each new student adds one X, so 7 Xs plus 3 more students gives a new total of 10 Xs on the line plot.
8. A Grade 3 line plot shows 8 Xs above 1 pet and 5 Xs above 0 pets. So 8 students have at least 1 pet.
The 8 Xs above 1 pet are the students with at least 1 pet, while the 5 Xs above 0 pets had none.
9. If a Grade 3 line plot has values 0 to 5 and only 2 has zero Xs, the range still goes from 0 to 5.
The scale on a line plot still spans from least to greatest values, even if some columns have zero Xs in them.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Tallest stack of Xs on a Grade 3 line plot
→ Mode of the data
Mode of the data
Total students on a Grade 3 line plot
→ Sum of all Xs
Sum of all Xs
Each X on a Grade 3 line plot
→ One data point
One data point
Column with zero Xs on a Grade 3 line plot
→ No students with that value
No students with that value
Each idea pairs with its meaning: tallest stack is the mode, total Xs equal total students, each X is one data point, and an empty column means no one had that value.