The worldwide number (in millions) of a particular phone sold can be approximated by the function f(x)=-875+403 Inx, where x 11 corresponds to 2011 (a) What was the number of worldwide sales for the particular phone in 2015? (b) If the model continues to be accurate, what was the first full year in which the particular phone sales exceed 262 million? (a) To find the number of worldwide sales in 2015, substitute) for x in the function. (Simplify your answer.) The number of worldwide sales for the particular phone in 2015 was approximately (Type an integer or decimal rounded to the nearest tenth as needed) (b) The first full year in which the particular phone sales exceed 262 million is million