The Houston Astrodome was the first baseball
and football stadium to be completely
enclosed. It was completed in 1965 at a cost
of 45.35 million dollars. Construction costs
have increased by approximately 6% each year
since 1965.
If this rate were to continue, how much
would it have cost to build the Astrodome in
2012?
Let x = the year
Let y = the cost to build
When x = 1965, y = 45.35 (million dollars)
When x = 1966, y = 45.35 + 0.06(45.35) = 48.071 (million dollars)
We find the equation of the line which passes through the
points (1965,45.35) and (1966,48.071)
We use the slope formula:
m =
where (x1,y1) = (1965,45.35)
and where (x2,y2) = (1966,48.071)
m =
We use the point-slope formula:
y - y1 = m(x - x1)
where (x1,y1) = (1965,45.35)
y - 45.35 = 2.721(x - 1965)
y - 45.35 = 2.721x - 5346.765
y = 2.721x - 5301.415
Sobstitute x = 2012:
y = 2.721(2012) - 5301.415
y = 173.237 million dollars or $173,237,000
Edwin