Question

Mrs. Daniels, an English teacher, is having her students track the number of words they read in a book. She took their data and

created the graph below.
What is the rate of words per page?
Word Count
10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
Words in a Book
2.5 5 7.5 10 12.5 15 17.5 20 22.5 25
Page Count

Answer 1

There is 200 words per page.

Step-by-step explanation:

1. Know that the rate of words per page is also the slope (m) in the linear equation (y = mx +b).

2. To solve for the slope, we can use the equation
`m=(y_2-y_1)/(x_2-x_1)`.

3. Let's choose the coordinates to plug into the equation. This line is linear, so you could choose any point. However, for the sake of this problem, I will choose (5, 1000) as point 1 and (10, 2000) as point 2; differentiating between the two points is important as the subscripts in the equation tell you which value is which.

4. Plug the identified points from Step 3 into the equation from Step 2.
`m=(2000-1000)/(10-5)`.

5. Solve the equation; solve for m.

• Subtract:
  `m=(2000-1000)/(10-5)=(1000)/(5)`
• Divide:
  `m=(1000)/(5)=200`

6. m (the slope) is 200, therefore, the rate of words per page is 200 words per page.