Question

Use the magnitudes? (Richter scale) of the 120120 earthquakes listed in the accompanying data table. Use technology to find the? range, variance, and standard deviation. If another? value, 7.507.50?, is added to those listed in the data? set, do the measures of variation change? much

3.31
2.45
2.56
2.42
2.78
2.41
2.19
2.42
1.91
1.44
2.84
1.71
2.00
2.35
2.34
2.72
4.71
2.86
3.37
2.69
2.78
3.46
3.99
3.00
3.84
3.47
3.10
2.94
2.70
3.62
2.85
2.38
3.03
3.23
2.61
3.62
3.22
2.70
2.35
2.43
2.83
3.96
2.53
2.91
2.98
3.45
2.27
2.56
2.90
3.13
2.19
1.13
1.95
4.03
2.58
2.83
2.36
2.29
1.51
2.81
1.94
1.59
2.44
2.36
2.06
1.55
3.22
1.50
1.83
2.54
1.65
2.36
2.42
2.08
2.20
2.76
2.00
2.80
2.41
2.67
1.68
2.88
1.85
2.01
1.83
2.53
1.99
2.18
3.62
1.52
3.19
2.46
1.86
1.48
2.75
3.27
3.83
2.74
2.43
2.71
2.51
1.62
2.17
3.02
2.32
1.49
1.92
2.33
2.66
1.42
1.39
1.81
2.25
2.29
2.46
1.77
2.40
2.43
2.48
2.44

Answer 1

Following table shows the descritive statistics:

Descriptive statistics
	X
count	120
mean	2.5198
sample standard deviation	0.6537
sample variance	0.4273
minimum	1.13
maximum	4.71
range	3.58

The range is: 3.58

The standard deviation is: 0.6537

The variance is: 0.4273

----------------------

After adding 7.50, the descritpve statistics will be:

Descriptive statistics
	X
count	121
mean	2.5609
sample standard deviation	0.7929
sample variance	0.6287
minimum	1.13
maximum	7.5
range	6.37

It shows that all statistics increased.