In 2009, 2012, and 2015, the number (in millions) of smart phones sold in the world was 172.4, 680.1, and 1423.9, respectively.

(a) Let t represent time in years since 2009, and let S represent the number of smart phones sold in millions. Determine M, A, and k for a logistic model, S (t) = M/1+Ae^−kt, that fits the given data points.

(b) What is the long-term expected maximum number of smart phones sold annually? That is, what is

(c) In what year does the model predict that smart phones sales will reach 98% of the expected maximum?

Transcribed Image Text:

lim S (t) 1-00 →00