Any times you see the phrase: "Rate of Change", or even sometimes just the word "Rate" think slope.
The word slope is just a fancy word that means the rate of change.
Rate of Change is just a fancy phrase meaning how much does something change over some amount of time.
So in this case our rate of change will have the units of inches per year.
Let's get to the problem at hand!
We'll need to find slope / the rate of change (the two are interchangeable with each other).
Let's go over the formula for slope:
m = (y2 - y1) / (x2 - x1)
First we will need to label each of the "coordinated points (the two numbers that go together in a pair)" with either (x1,y1) or (x2,y2).
A Giant Red Oak's diameter in 1965 was 248 inches. Keep in mind time is ALWAYS going to be X in rate of change problems (and most all problems for that matter).
(1965,248)
(X1,Y2)
(2005,251)
(X2,Y2)
Plug in the values into the equation!
m = (y2 - y1) / (x2 - x1)
m = (251 - 248) / (2005 - 1965)
m = (3) / (40)
Type that into a calculator to get a decimal value over 1.
m = 0.075 inches per 1 year.
Or...
m = 0.075in / 1 year
The y intercept and the gradient
Answer:
The worth of the car after 6 years is £2,134.82
Step-by-step explanation:
The amount at which Dan buys the car, PV = £2200
The rate at which the car depreciates, r = -0.5%
The car's worth, 'FV', in 6 years is given as follows;

Where;
r = The depreciation rate (negative) = -0.5%
FV = The future value of the asset
PV = The present value pf the asset = £2200
n = The number of years (depreciating) = 6
By plugging in the values, we get;

The amount the car will be worth which is its future value, FV after 6 years is FV ≈ £2,134.82 (after rounding to the nearest penny (hundredth))