Answer:
5.5%
Step-by-step explanation:
To find the interest rate, use the equation: I = prt
I = Interest = $6,600
p = principal = $15,000
r = rate = unknown
t = time = 8 years
Now plug the numbers into the equation.
6,600 = 15,000 * r * 8
6,600 = 120,000 * r
Now isolate the variable by dividing both sides of the equation by 120,000.
0.055 = r
Now change the rate to a percent by moving the decimal point 2 digits to the right.
5.5% = r OR r = 5.5%
The equation for working out the slope of a linear line is: , where x and y are the coordinate pairs.
So just pick two of the purple dots on the graph and fill in the equation.
I'll pick the dot that's (-4, 1) and (4, -7).
Now I just do , which is just when simplified.