# Help exponential function

1. Sep 17, 2011

### schan11

Help!!! exponential function

Please look at the attachment for the question!!!

#### Attached Files:

• ###### IMG_0002.jpg
File size:
51.1 KB
Views:
92
2. Sep 17, 2011

### Harrisonized

Re: Help!!! exponential function

An exponential function is a function f(x)=ax, where a is the ratio between entries. Since you have a bunch of data, divide between entries to find the ratio, a. Then average them to get the average ratio, and use this average ratio to find the missing values.

3. Sep 17, 2011

### schan11

Re: Help!!! exponential function

But how do you work out the function?

4. Sep 17, 2011

### Harrisonized

Re: Help!!! exponential function

Let's take the first two entries as an example.

On day 21/5, we have 3 cases of H1N1. On day 22/5, we have 7 cases of H1N1.

What's 7/3? 2.333.

On day 22/5, we have 7 cases of H1N1. On day 23/5, we have 12 cases of H1N1.

What's 12/7? 1.714.

Hopefully by now you've noticed that these are the values in the third column.

5. Sep 18, 2011

### Staff: Mentor

Re: Help!!! exponential function

It might be instructive to plot the raw data on semilog graph paper. (Search on google, and print out a sheet of it.) The curve of best fit should be a straight line. Measure its slope. From this you can work out the equation you seek. This should support the figures in the right-most column of your data. This exercise amounts to graphically taking an average of the numbers in the right column, and, if it hadn't already been done, would save calculating those numbers.

Last edited: Sep 18, 2011
6. Sep 18, 2011

### HallsofIvy

Staff Emeritus
Re: Help!!! exponential function

Even after several responses, there is no attempt at all by the original poster to work the problem himself. Thread closed.