Line graphs, line plots, and the mean

Advanced Math 5 · Unit 9 · line-plots-mean · Teacher edition

line-plots-mean

Name ______________________________Date ______________

1.
Five students scored $7$ , $12$ , $9$ , $15$ , and $12$ on a quiz. What is the mean score?
Answer: ______________
2.
The line plot below shows the lengths of $8$ ribbons.

Length (m) $\frac{1}{2}$ $\frac{3}{4}$ $1$
Number of ribbons $3$ $2$ $3$

What is the mean length, in metres?
Answer: ______________
3.
The line plot below shows how far $10$ paper airplanes flew.

Distance (m) $1$ $1\frac{1}{2}$ $2$ $2\frac{1}{2}$
Number of airplanes $2$ $3$ $4$ $1$

What is the mean distance, in metres?
1. (A)
  $2.5$
2. (B)
  $1.75$
3. (C)
  $1.7$
4. (D)
  $4.25$
5. (E)
  $17$

Length (m)	$\frac{1}{2}$	$\frac{3}{4}$	$1$
Number of ribbons	$3$	$2$	$3$

Distance (m)	$1$	$1\frac{1}{2}$	$2$	$2\frac{1}{2}$
Number of airplanes	$2$	$3$	$4$	$1$

Answer key — Line graphs, line plots, and the mean

1.
11line-plots-mean-01
Total $= 55$ over five scores. Mean $= 55 \div 5 = \mathbf{11}$ .
2.
3/4line-plots-mean-02
Total $= \frac{3}{2} + \frac{3}{2} + 3 = 6$ m over $3 + 2 + 3 = 8$ ribbons. Mean $= 6 \div 8 = \mathbf{\frac{3}{4}}$ m.
3.
(C)
$1.7$
line-plots-mean-03
Total $= 17$ m; $10$ airplanes. Mean $= 17 \div 10 = \mathbf{1.7}$ m. ( $2.5$ is $10$ airplanes $\div$ $4$ columns; $1.75$ averages the four column labels and ignores how many airplanes are in each; $4.25$ is $17 \div 4$ ; $17$ is the total.)