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In a class survey a Professor asked his students to guess how many irr
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07 Mar 2024, 23:42
07 Mar 2024, 23:42
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In a class survey a Professor asked his students to guess how many irregular blocks could be fit into a jar. The chart above is the numbers guessed and the frequency of each guessed number. What is the standard deviation in the guesses?
A. 2.7
B. 2.9
C. 4
D. 7.45
E. 18
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Free Materials for the GRE General Exam - Where to get it!!
GRE Geometry Formulas
GRE - Math Book
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Free Materials for the GRE General Exam - Where to get it!!
GRE Geometry Formulas
GRE - Math Book
Re: In a class survey a Professor asked his students to guess how many irr
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18 Jun 2024, 07:56
18 Jun 2024, 07:56
Expert Reply
First the mean of the values we do have in the table
\(\frac{13+14(3)+15(2)+17(7)+18+20(5)+21+25}{1+3+2+7+1+5+1+1}=17.52\)
Now the differences from the mean and the data point and square them
\(\frac{4.5^2+3(3.5^2)+2(2.5^2)+7(0.5^2)+(0.5^2)+5(2.5^2)+3.5^2+7.5^2}{21}=8.154\)
Take the square root of \(\sqrt{8.154}=2.855\)
B is the answer
\(\frac{13+14(3)+15(2)+17(7)+18+20(5)+21+25}{1+3+2+7+1+5+1+1}=17.52\)
Now the differences from the mean and the data point and square them
\(\frac{4.5^2+3(3.5^2)+2(2.5^2)+7(0.5^2)+(0.5^2)+5(2.5^2)+3.5^2+7.5^2}{21}=8.154\)
Take the square root of \(\sqrt{8.154}=2.855\)
B is the answer
gmatclubot
Re: In a class survey a Professor asked his students to guess how many irr [#permalink]
18 Jun 2024, 07:56
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