The formula for compound interest is A = P(1+r)', where A is the accrued amount after t
years, P is the starting principal, and r is the annual interest rate expressed as a decimal. If
you invest $1000 at an interest rate of 7% and leave it there for 30 years, what would your
ending balance be? Round your answer to the nearest cent.

for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)

(-5,-28)

i graphed to on desmos.