Suppose that a person 6 feet tall weighs 180 pounds and another person is 4 feet tall and weighs 80 pounds fit a linear equation to the points and estimate the weight of a person who is 5.5 feet tall?

Let x represent the height of the person and y the weight.
y - 180 = (80 - 180)/(4 - 6) (x - 6)
y - 180 = -100/-2 (x - 6) = 50(x - 6) = 50x - 300
y = 50x - 300 + 180 = 50x - 120
y = 50x - 120

A person 5.5 feet tall will weigh 50(5.5) - 120 = 275 - 120 = 155 pounds.

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