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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: Comatose on September 19, 2011, 06:35:46 pm

Title: How do you do VCAA 2010 Exam 1 Core Q3?
Post by: Comatose on September 19, 2011, 06:35:46 pm

title says it all. question 3 of core exam 1 2010.

Title: Re: How do you do VCAA 2010 Exam 1 Core Q3?
Post by: jasoN- on September 19, 2011, 06:57:22 pm

We know the median is 180 from the boxplot and since the distribution looks approx symmetric, we can equate mean ~180
From there, we know that 1 standard deviation away from the mean accounts for ~68% of values
Looking back at the histogram, add up columns to the left and right of the mean (1 by 1) until u get approx 68%
By using a ruler (hells yea) u get values 21%, 16%, 13.5%, 14.5% (ROUGHLY) which adds up to a total of 64.5% which is close enough to 68%
therefore 68% is covered by 2 bars to the left of the mean, 2 bars to the right of the mean
S.D = 180-178 = 2ºC (or 182-180)

This was just how I did it, can't really think of a more systematic approach to it

Title: Re: How do you do VCAA 2010 Exam 1 Core Q3?
Post by: Comatose on September 19, 2011, 07:02:34 pm

thank you very much. that made things perfectly clear