Question

In: Statistics and Probability

Compute the range and sample standard deviation for strength of the concrete? (in psi) 3960, 4140,...

Compute the range and sample standard deviation for strength of the concrete? (in psi)

3960, 4140, 3300, 3200, 2950, 3820, 4140, 4010

Expert Solution

SOLUTION:

From given data,

Compute the range and sample standard deviation for strength of the concrete? (in psi)

3960, 4140, 3300, 3200, 2950, 3820, 4140, 4010

Where we have to find

Compute the range:

Formula for range = maximum value - minimum value

Where,

maximum value = 4140

minimum value = 2950

range = 4140 - 2950

range = 1190 psi

Compute the standard deviation

	(-)²
3960	(3960-3690)² =72900
4140	(4140-3690)² =202500
3300	(3300-3690)² =152100
3200	(3200-3690)² =240100
2950	(2950-3690)² =547600
3820	(3820-3690)² =16900
4140	(4140-3690)² =202500
4010	(4010-3690)² =102400
=3690	(-)² = 1537000

= 3960+4140+3300+3200+2950+3820+4140+4010 = 29520

Sample size = n = 8

= / n = 29520/8 = 3690

Standard deviation = S = sqrt((-)² / (n-1))

S = sqrt(1537000/ (8-1))

S = 468.58449

S = 468.5 psi

orchestra answered 2 years ago

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