# Thread: geometric sequence or an aplplication of exponential growth

1. ## geometric sequence or an aplplication of exponential growth

The number of cellular phone customers of a particular telephone company increased by an average of 40%/a from 1994 to 1998. If there were 963 300 customers on January 2, 1998, then the number of customers on January 2, 1994, to the nearest hundred, would have been

t5=963300, n=5

tn=a*r^(n-1)

My question is how they determine ratio=1.4?? please somebody can give me an easy explanation!!

2. ## Re: geometric sequence or an aplplication of exponential growth

When some quantity is increased by 40%, then there is 140% of the original or 140/100 = 1.4 times the original.

3. ## Re: geometric sequence or an aplplication of exponential growth

"Increased by 40%" means it was 40% more than before. "Before" it was 100% of course, so increasing by 40% gives 140% which is the same as a multiple of 1.40.

(MarkFL did it to me again!)

4. ## Re: geometric sequence or an aplplication of exponential growth

Originally Posted by HallsofIvy
...
(MarkFL did it to me again!)
See, that's what happens when you take the time to explain more thoroughly...