Question on Calculations

phairiston 

I came up with two different ways to do this, ending at the end of year 4 a little bit apart. Your words are open to interpretation however, so there may be still more ways to do this.

The simplest way is to take both percentages (loss or gain percent PLUS the "pull" percent) entered as negatives or positives, apply the sum of those percentages to the amount starting the year and add the result to the start of the year. (Note: adding a negative number is the same as subtracting a positive of the same absolute value; so by adding, I'm dealing with the negative or positive percentages consistently.)

That results in these numbers

The other way was to take the two percentages and apply them as distinct steps, still beginning with the same year one start, but taking (for example) the loss of 30% from 300,000 and then the pull of 4% from the result of the first calculation. And so on for the subsequent years. That produces these numbers.

To change the starting figure to 195,000 you'd just change the numbers in yellow in the attached spreadsheet.

By the way, your last line of "instruction" you used a double negative, I think inadvertently.

year 4 they lose -3% and pull 4.6% from that amount. 

I chose to take that to mean "they lose 3%"; were I to take it literally, a negative loss would be a gain. IF in fact that's what you meant, just change the -3% to 3%.  But you need to be careful in math with negatives and positives when you're multiplying and dividing, adding and subtracting.