Measuresof Variability
Number of arrests 

Bob 
0 
Barbara 
0 
Johny 
1 
Sam 
1 
Ken 
2 
Nicole 
2 
Sarah 
3 
Stuart 
3 
Julie 
5 
Keith 
8 

Range of the sample
Rangeis usually calculated by getting the difference between the highestand the lowest value.
Range=maximumvalueminimum value
=80
=8

Interquartile Range
Theinterquartile range is a measure of variability that largely concernsitself with the division of data sets in quartiles. Quartiles dividea data set that is ordered in four equal sections. The values thatare obtained and divide each section is known as first, second andthird quartiles.
Interquartilerange =3^{rd}quartile – 1^{st}quartile
Positionfor 1^{st}quartile ===2.75≈ 3
The1^{st}quartile=1
Positionfor 3^{rd}quartile ===8.25≈ 9
The3^{rd}quartile=3
Interquartilerange =31=2

Variance of the sample
=
Samplemean=== 2.5
=
=
==6.0556
Samplevariance is 6.0556.

Standard deviation of the sample
Samplestandard deviation=
=2.46
Fromthe above calculations, the difference between the maximum arrestsand the minimum arrests is 8. The interquartile range is the rangethat contains 50% of the number of arrests in this sample (Pinedaet al., 2013). From the calculations and in this case among the middle 50% of theoffences committed the difference between the highest arrests that isthe 3^{rd}quartile and the least arrests that is the 1^{st}quartile is 2 arrests.
Thenumber of arrests in this sample on average deviate away from theaverage number of arrests of the inmates by 2.46. The variance is theaverage squared differences from the mean of the number of arrests ofthe inmates.
References
Pineda,M., Aguilar, A., Axotla, J. C., León, F., & García, O. (2013).TEACHING THE TOPIC OF CENTRAL MEASURES TENDENCY AND VARIABILITYTHROUGH OF ELEARNING COURSE, IN THE CLASS OF STATISTIC IN THE HIGHERFACULTY OF STUDIES CUAUTITLAN. EDULEARN13Proceedings,45544558.