Question

The table and scatterplot show the price of a barrel of crude oil over five years.



Annual Average Domestic Crude Oil Prices
Year Price per Barrel ($)
1 27.69
2 37.66
3 50.04
4 58.30
5 64.20




image.png


The variable x represents time, in years, and y represents the price of crude oil per barrel, in dollars. According to the scatterplot, which equation BEST represents the relationship between the year and the price of crude oil?


y
=
0.1
x
−
2.0


y
=
0.2
x
−
5.9


y
=
9.4
x
+
19.5


y
=
11.2
x
+
16.1

Answer 1

Compute the slope from year 1 to 5: (64.20 − 27.69)/(5 − 1) = 36.51/4 ≈ 9.13.
Find the intercept: b ≈ 27.69 − 9.13(1) ≈ 18.56.

The line y ≈ 9.13x + 18.56 is closest to y = 9.4x + 19.5, so the best choice is y = 9.4x + 19.5.