Answer:
Linear Equation: P = 0.008T + 0.13
Price of stamp in 2015 = $0.45
Step-by-step explanation:
From 1975 to 2005 [30 years], the price increased from 0.13 to 0.37 [0.24].
This means the rate of change (slope) is 0.24/30 = 0.008
This means Price changed (increased) by $0.008 per year.
Slope = 0.008
The y-intercept (P) is at the starting point which is at T = 1975, the price was 0.13. Hence y-intercept is 0.13
The equation of a line is given as
P = mT + b
Where m is the slope and b is the y-intercept
Now, we can write the linear model equation as:
P = 0.008T + 0.13
To find the price of stamp in 2015, we see that this is 40 years later after 1975. So we plug in 40 into T in the equation found above:
P = 0.008(40) + 0.13
P = $0.45