Measure Of Dispersion/variation

Question 1

Measures of dispersion

Answer 1

Range
Mean/average deviation
Standard deviation
Quartile deviation

Question 2

Range?

Answer 2

Difference between highest n lowest value or difference between mid point of extremes of group( when grouped data are taken)
It’s the simplest measure of deviation
Provide information concerning scatter within series

Question 3

Mean deviation

Answer 3

Avg of deviations from arithmetic mean

Question 4

Standard deviation

Answer 4

Most frequently used measure sum of squared deviation from mean/no. Of value -1
N-1 if sample size <30

Question 5

Variance

Answer 5

Sum of squared deviations from mean/no. Of value -1

SD=positive square root of variance

Question 6

Co efficient of variation

Answer 6

CV=SD/mean x100

Used to compare variability of 2distribution