Geometric Series: Find 3 Numbers for 5 Components

[Femme_physics]

Homework Statement

You must enter 3 numbers between 31 and 496 so there will be an increasing geometric series with 5 components.

The Attempt at a Solution

It tells me I'm off. That q=2. But how?

http://img716.imageshack.us/img716/8895/300xk.jpg

 

[I like Serena]

Hey FP :)

Multiply instead of add?

 

[vela]

With a geometric series, you multiply by q to get successive terms:

$$\begin{align*} a_2 & = a_1 q \\ a_3 & = a_1 q^2 \\ a_4 & = a_1 q^3 \\ a_5 & = a_1 q^4 \end{align*}$$

Do you see your mistake now?

 

[Femme_physics]

Hey FP :)

Multiply instead of add?

w00t! :) I hope I have all the formulas at the test so I can relook them. Thanks, ILS! And vela, too :)