Question

You are given

n = 5

measurements: 3, 1, 4, 5, 5.

(a) Calculate the sample mean,

x.

x =

(b) Calculate the sample variance, s², using the formula given by the definition.

s² =

(c) Find the sample standard deviation, s. (Round your answer to three decimal places.)

s =

(d) Find s² and s using the computing formula. (Round your answer for s to three decimal places.)

s2 =
s =

Compare the results with those found in parts (b) and (c).

The values found in (b) and (c) are lower than the values found in part (d).The results are identical.    The values found in (b) and (c) are higher than the values found in part (d).

Answer 1

(a)

Following table shows the calculations:

	X	(X-mean)^2
	3	0.36
	1	6.76
	4	0.16
	5	1.96
	5	1.96
Total	18	11.2

(b)

(c)

(d)

Following table shows the calculations:

	X	x^2
	3	9
	1	1
	4	16
	5	25
	5	25
Total	18	76

The results are identical.  

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