Carcass wrote:
Attachment:
GRE The scatterplot above shows the numbers of incidences.jpg
The scatterplot above shows the numbers of incidences of melanoma, per 100,000 people from 1940 to 1970. Based on the line of best fit to the data, as shown in the figure, which of the following values is closest to the average yearly increase in the number of incidences of melanoma?
A. 33,000
B. 23,000
C. 13,000
D. 0.33
E. 0.13
We just need two data points to determine the average yearly increase in the number of incidences of melanoma
The line of best fit tells us that:
In 1940, the number of incidences of melanoma was about 120,000
In 1970, the number of incidences of melanoma was about 500,000
500,000 - 120,000 = 380,000
So, over a 30-year period (from 1940 to 1970) the number of incidents increased by 380,000
So, the average annual increase ≈ 380,000/30 ≈ 13,000
Answer: C
Cheers,
Brent