help with Stats

[_Liam]

sally has drawn two comparative pie charts showing her annual household expenditure. her total expenditure in 1995 was £10 762, and she uses a pie-chart of radius 4 cm. her total expenditure in 2002 was £19 680. calculate the radius, to 3 significant figures, Sall needs to use for her pie-chart fir 2002.

+ rep to whoever helps

[Soka]

sally has drawn two comparative pie charts showing her annual household expenditure. her total expenditure in 1995 was £10 762, and she uses a pie-chart of radius 4 cm. her total expenditure in 2002 was £19 680. calculate the radius, to 3 significant figures, Sall needs to use for her pie-chart fir 2002.

+ rep to whoever helps

10762 pieces with radius of 4 cm
area of this circle = pie,r squared = pie x 16
= 50.3 cm squared is area of 1995 circle
50.3 divided by 10762 = 0.00467 cm squared represents 1 pound

so you do 0.00467 x 19680 = 91.9 cm squared is area of 2002 circle

area = pie, r squared and rearranging
radius = square root (area divided by pie)
radius = square root (area divided by 91.9)
= 5.41 cm [3 s.f]

for each stage, i put the numbers to 3 s.f
hope this helps, although it might be a bit late as i've had my gcse statistics on thursday you've probably had yours now unless your in year 10 :)

[_Liam]

Actually i'm in year9 just starting it.

I got to that answer just forgot toclose the thread +rep anyway