Question

The scatter plot shows the number of animal cells Clara examined in a laboratory in different months:

Plot ordered pairs 1, 20 and 2, 60 and 3,100 and 4, 140 and 5, 180

What is the approximate predicted number of animal cells Clara examined in the 9th month?

Answer 1

Answer: In the 9th month the approximate number of animal cells Clara examined is 340.

Explanation:

1. The first step is to look for a common increase between each point. You can do this by subtracting the second month by the first month.

Example: 60-20=40

100-60=40

140-100=40

180-140=40

So of the 5 points the common increase is 40.

2. Once you find the common increase you can evaluate the problem. Since it asks for the 9th month take the amount from month 5 and add 40 until you reach the ninth month.

Example:

Month 5 = 140 + 40 = 180

Month 6 = 180 + 40 = 220

Month 7 = 220 + 40 = 260

Month 8 = 260 + 40 = 300

Month 9 = 300 + 40 = 340

So now with this table you can see that in the 9th month Clara examined about 340 animal cells that month.