In January 2008, the average number of posts on Twitter was 300 thousand tweets per day. In January 2011, that number had increased to 100 million tweets per day.

Question

create an explicit exponential formula relating years since 2008 (n) and average number

of tweets per day in January of that year (Tn); measure average number of tweets per

day in units of millions of tweets.

Answer 1

t0= y=.3

t3 =y=100

y=ab^x x=n

.3 = ab^0=a(1)=a

y=.3b^x

100=.3b^3

b^3= 100/.3=333.333

b= cube root of 333 1/3

y= .3(333 1/3)^x/3

tn =.3(333 1/3)^n/3