# Thread: Help with finding Annual Rate of Increase/Decrease

1. ## Help with finding Annual Rate of Increase/Decrease

Data table in attachment.

Determine, to the nearest tenth of a percent, the average annual rate of increase/decrease for each school.
I really have no clue what to do here. It's related to Exponents/Logs I'm pretty sure, I didn't do so hot in that unit.. Any help would be awesome.

2. Hello, fkhnksaha!

It's much simpler than you think . . .

Determine, to the nearest tenth of a percent,
the annual rate of increase/decrease for each school.

. . $\begin{array}{|c|c|c|} \text{Year} & \text{School \#1} & \text{School \#2} \\ \hline 1995 & 1353 & 449 \\ 1996 & 1391 & 517 \\ 1997 & 1343 & 519 \\ 1998 & 1142 & 518 \\ 1999 & 1167 & 574 \\ 2000 & 1087 & 620 \\ 2001 & 999 & 635 \\ 2002 & 862 & 605 \\ 2003 & 818 & 619 \end{array}$

Formula: . $\frac{x_2-x_1}{x_1}$ . . . and convert to a percent.

. . In baby-talk: the second term minus the first, divided by the first.

School #1

Year 1995-1996: 1353 → 1391

. . We have: . $\frac{1391-1353}{1353} \:=\:\frac{38}{1353} \:=\:0.028085735$

Therefore, the rate of increase is: . $2.8\%$

Year 1996-1997: 1391 → 1343

. . We have: . $\frac{1343-1391}{1391} \:=\:\frac{-50}{1393} \:=\:-0.035945363$

Therefore, the rate of decrease is: . $-3.6\%$

Think you can do the rest of them now?

3. Oh my, I feel stupid right now. I guess groups of questions aren't always related. Thanks for helping me realize the simplicity of it, Soroban.

4. To find the average do we just take the rate of increase/decrease of each year, add them, then divide by number of terms?

5. Originally Posted by yaphetkotto
To find the average do we just take the rate of increase/decrease of each year, add them, then divide by number of terms?
That's what I would do.