Question

This data is from a sample. Calculate the mean, standard deviation, and variance. Suggestion: use technology. Round answers to two decimal places.

x

32.5

34.8

49.7

45

18.1

35.2

42.6

10.6

20.8

Mean =

Standard Deviation =

Variance =

Ooops - now you discover that the data was actually from a population! So now you must give the population standard deviation.

Population Standard Deviation =

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Answer 1

	x	(x-mu)^2
	32.5	0.126736
	34.8	7.054336
	49.7	308.2131
	45	165.2767
	18.1	197.2339
	35.2	9.339136
	42.6	109.3279
	10.6	464.1439
	20.8	128.6863
Sum=	289.3	1389.402
Mean=	32.14444

As we know Mean =sum of x values/n

Sample Variance=summation of (x-mu)^2/(n-1)=1389.402/(9-1)=173.6753

Sample Std dev=sqrt(variance)=sqrt(173.6753)=13.1786

Population Variance= Summation of (x-mu)^2/n= 1389.402/9=154.378

Population std dev= Sqrt(Variance)=12.4249