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The weight in pouns of ten men, so N = 10 are as follows: 152 196, 144, 139, 166

ID: 3217515 • Letter: T

Question

The weight in pouns of ten men, so N = 10 are as follows: 152 196, 144, 139, 166, 83, 186, 157, 140, 138

Find the Mean of the weight in pounds.

Find the standard deviation of the weight in pounds.

(Deviation) 2

(x-mean)2

                                                                                                          Total:

Remember, the standard deviation is the square root of the variance, S2

S2 = Sum (x - x))2 = sum from your third column/N-1

         ______________

               N - 1

What % of this data is within one standard deviation of the mean? Show the interval you used.

What % of this data is within 2 standard deviations of the mean? Show the interval you used.

weight in pounds(S) Deviation from Mean

(Deviation) 2

(x-mean)2

Explanation / Answer

from above data

mean =150.1

std deviation =(8610.9/9)1/2 =30.932

hence 1 std deviation away values =(150.1-30.932 ; 150.1+30.932)=(119.168 ; 181.032)

as 7 out of 10 values fall into that interval ; hence 70% of this data is within one standard deviation of the mean

for 2 std deviation away values =(150.1-2*30.932 ; 150.1+2*30.932)=(88.237 ; 211.963)

as 9 out of 10 values fall  into that interval ; hence 90% of this data is within one standard deviation of the mean

X (X-mean)^2 152 3.61 196 2106.81 144 37.21 139 123.21 166 252.81 83 4502.41 186 1288.81 157 47.61 140 102.01 138 146.41 total 1501 8610.9 Mean=total/10 150.1