An October 2009 article in The Industry Standard states that "independent Twitter data shows exponential tweet growth." GigaTweet, an independent tweet-counting service, reports that the number of tweets was 5.0 billion in October 2009. In April 2009, the number of tweets was 1.6 billion.

The exponential growth model that fits with these data, where t is the number of months after April 2009

and p is the number of tweets in billions is p ( t ) = 1.6 e 0.1899057 t

Use the model to predict when there will be 20.0 billion tweets. (Round your answer to the nearest whole number.)

	14 months after April 2009
	13 months after April 2009

	11 months after April 2009
	12 mounts after April 2009