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.Answer is: This problem can be treated as a geometric sequence or an application of exponential growth. As a sequence r=1.4 since 40% growth makes each term 1.4 times the previous term. There are 5 terms from 1994 to 1998, so t(5)=963300, n=5
t(n)=a*r^(n-1) so, 963300=a(1.4)^(5-1)
((963300)/(1.4)^4) = a a=250800 Why r=1.4?????

Question

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.Answer is: This problem can be treated as a geometric sequence or an application of exponential growth. As a sequence r=1.4 since 40% growth makes each term 1.4 times the previous term. There are 5 terms from 1994 to 1998, so t(5)=963300, n=5
t(n)=a*r^(n-1) so, 963300=a(1.4)^(5-1)
((963300)/(1.4)^4) = a a=250800 Why r=1.4?????