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Hi could anyone please guide me on how I would go about calculating the percentage of a specific sector from this Pi-chart. I think I am suppose to use data from the bar chart and apply it to the pie-chart but I don't really know how.

The question is

According to the data provided, in 2005 the total expenditure (outgoings) on Advertising and Sales and Distribution was closest to which of the following amounts a)50,000,000 b)35,000,000 c)30,000,000 d)$5,000,000 e)3,000,000 Ans is a

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Measure the angle of the ad sector, divide by $2\pi$ and multiply by \$165 millions ... –  draks ... Jul 28 '12 at 11:27
    
Measure it - How ? –  MistyD Jul 28 '12 at 11:32
    
Print it and use a triangle... –  draks ... Jul 28 '12 at 11:34
    
I am sure we are not allowed to use protractors or triangles. Cant it be solved without Ds or triangles ? –  MistyD Jul 28 '12 at 11:45
    
Meaure the arc length of the sector and the total circumference, divide and multiply... –  draks ... Jul 28 '12 at 12:18
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2 Answers 2

up vote 4 down vote accepted

Ignore the bar graph. Looking at the relevant sections of the pie chart, estimate their area as a fraction of the whole. I would estimate it at about $1/3$ of the total area, but in any case it is certainly more than $1/4$ and less than $1/2$. Now look at the possible answers as fractions of the total $165$ million. Only one falls within the required range.

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So I guess Ill have to rely on estimation. For instance that area is round about 30%. which is very close to the answer. –  MistyD Jul 28 '12 at 12:47
    
Unless the angles were very well constructed and you have a good protractor. –  Michael Chernick Jul 29 '12 at 13:40
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If you look at the pie chart, you can see that red, green and purple take away roughly 50% total. From that 50% every part takes away around 33%. You are looking for the value of green+purple.

With our thoughts above, we can estimate that green and purple take around 33% of the pie. So with 100% = 165 mil, 33% would be around 55 mil. Now take the answer closets to this, which is 50 mil.

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