According to an article in the NY Times Sales of water in st

According to an article in the NY Times \"Sales of water in standard lightweight plastic bottles grew at a rate of more than 20 percent every quarter from 1993 to 2007.\" (i) How many quarters are there from the beginning of 1993 to the beginning of 2007? Express your answer as an integer. quarters (ii) For sales to increase 20% per quarter from the beginning of 1993 to the beginning of 2007, how much of an overall increase is that? ( Hint: think of compounding for several time periods! ) Express your answer rounded correctly to the nearest whole number, not in percent form! times

Solution

quarter of a year = 3months out of 12 months

start 1993 to start 2007 -> no of years= 14 ,

i) no,of quarters= 14*4 = 56

ii) Overall increase = (1+ 20/100)^56 = 1.2^56 = 27173.76 = 27174