Question

Using Minitab, calculate the mean, standard deviation, variance, and median of the following four data sets. Comment on the results.

A	B	C	D
100	50	50	75
100	75	100	75
100	100	100	75
100	125	100	100
100	150	150	175

Answer 1

• First type data in worksheet

• Then Enable commands from menu bar. Also select Calc-->Column Statistics

• Select respective statistics

Variance = square of standard deviation

Minitab output:

MTB > Mean 'A'.
Mean of A
Mean of A = 100

MTB > StDev 'A'.
Standard Deviation of A
Standard deviation of A = 0

Variance of A
MTB > Let k1=STDEV(A)^2
MTB > print k1
Data Display
K1 0

MTB > Median 'A'.
Median of A
Median of A = 100

MTB > Mean 'B'.
Mean of B
Mean of B = 100
MTB > StDev 'B'.

Standard Deviation of B
Standard deviation of B = 39.5285

Variance of B
MTB > Let k2=STDEV(B)^2
MTB > print k2
Data Display
K2 1562.50

MTB > Median 'B'.
Median of B
Median of B = 100

MTB > Mean 'C'.
Mean of C
Mean of C = 100

MTB > StDev 'C'.
Standard Deviation of C
Standard deviation of C = 35.3553

Variance of C
MTB > Let k3=STDEV(C)^2
MTB > print k3
Data Display
K3 1250.00

MTB > Median 'C'.
Median of C
Median of C = 100

MTB > Mean 'D'.
Mean of D
Mean of D = 100
MTB > StDev 'D'.

Standard Deviation of D
Standard deviation of D = 43.3013

Variance of D
MTB > Let k4=STDEV(D)^2
MTB > print k4
Data Display
K4 1875.00

MTB > Median 'D'.
Median of D
Median of D = 75

Table:

	A	B	C	D
Mean	100	100	100	100
Standard deviation	0	39.5285	35.3553	43.3013
Variance	0	1562.50	1250.00	1875.00
Median	100	100	100	75

Mean of all four sets of data is same. Other quantities differ.