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10-57.

Marty has saved $\3000$, and he decides to divide it among three investments and see how his money grows over time. The table below shows his earnings over six months.

Month

Investment A

Investment B

Investment C

$0$

$\1000$

$\1000$

$\1000$

$1$

$\1010$

$\1010$

$\1001$

$2$

$\1020$

$\1020.10$

$\1004$

$3$

$\1030$

$\1030.30$

$\1009$

$4$

$\1040$

$\1040.60$

$\1016$

$5$

$\1050$

$\1051$

$\1025$

$6$

$\1060$

$\1061.50$

$\1036$

1. Describe the growth of each investment.

Investment A grows $\10$ per month.
Investment B grows at $1\%$ per month.
Investment C grows by quadratic rate.

2. Calculate the average rate of change of each investment from Month $4$ to Month $6$.

Remember that rate of change is another way of saying slope.
What is the equation for slope?

3. Assume each investment continues to grow in the same way it has grown during the first six months. If Marty plans to invest his money for many years, which investment is the best choice.

Depends on how many years but over a long time exponential is best.