the following chart shows a store?s records of coat sales over two years.\n2006\n2007\nif the trend shown in…

the following chart shows a store?s records of coat sales over two years.\n2006\n2007\nif the trend shown in these graphs stays constant, what percent of the market will parkas occupy in 2008? (round your answer to the nearest tenth.)\na. 16.5%\nb. 19.0%\nc. 21.9%\nd. 35.7%
Answer
Explanation:
Step1: Calculate total sales in 2006
$297 + 137+213 + 210+103=960$
Step2: Calculate total sales in 2007
$223+210 + 285+259+127 = 1104$
Step3: Calculate growth - rate of total sales
Growth rate $r=\frac{1104 - 960}{960}=\frac{144}{960}=0.15$
Step4: Calculate number of parkas sold in 2007
Number of parkas in 2007 is 210
Step5: Assume growth - rate of parkas is same as total sales growth - rate
Number of parkas in 2008 is $210\times(1 + 0.15)=210\times1.15 = 241.5$
Step6: Calculate total sales in 2008
Total sales in 2008 is $1104\times(1 + 0.15)=1104\times1.15 = 1269.6$
Step7: Calculate percentage of parkas in 2008
Percentage $=\frac{241.5}{1269.6}\times100%\approx19.0%$
Answer:
b. 19.0%