Answer:
$22
Explanation:
Given a table of popcorn volumes and prices, you want to know a reasonable price for 60 ounces of popcorn.
Table
Plotting the given sizes and costs on a graph, we see that the relationship is linear. Using the two points (size, cost) = (10, 6) and (20, 8), we find the relation to be ...
m = (y2 -y1)/(x2 -x1) = (8 -6)/(20 -10) = 2/10 = 0.2 . . . . slope
b = y1 -m(x1) = 6 -0.2(10) = 4 . . . . . . y-intercept
Then the equation of the line is ...
y = mx +b
y = 0.2x +4
Extrapolation
Using x=60, we find the corresponding price is ...
y = 0.2(60) +4 = 12 +4 = 16
A consistent price is $16 for a 60-ounce container of popcorn.
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Additional comment
The price equation suggests a fixed cost ($4) and a volume-related cost ($0.20 per ounce).