forum.virtualchallengemeets.com

There was a question on the District 2 test this year that read:
Tom Thumb grew in height 5% two years ago, 7% last year, and 11% this year. What was his percentage growth per year, on average, during this period? (nearest hundredth percent)
The answer is 7.64%, but I don't see how to get that. Another answer choice was 7.67%, so simply adding all three and dividing by three isn't right... help anyone?

given that his height is x...you are looking for a percent such that...

[unparseable or potentially dangerous latex formula]

where y is the average percent growth./100..

or... find the geometric mean of the three rates (they have to be in 1.xx form, not just .xx)

Cube root(1.05*1.07*1.11)
= 1.0763793363

oh, i see. thanks