Statistics

Question 1

Arithmetic Mean

Answer 1

Σxifi/Σfi

Question 2

Assumed Mean

Answer 2

Σfidi/Σfi + a

Question 3

Step Deviation Mean

Answer 3

(Σfiui/Σfi*h) + a

Question 4

Combined Mean

Answer 4

(n1x1 + n2x2)/n1+n2

Question 5

Median

Answer 5

l + (N/2-F) * h /f, where l = lower limit
N = Total number of observation
F = cumulative frequency of the preceding class
f = frequency of the median class
h = class interval

Question 6

Mode

Answer 6

l + (fo-f1/2fo-f1-f2)*h, where l = lower limit
fo= Frequency of modal class
f1 = Frequency of preceeding class
f2 = Frequency of suceeding class
h = class Interval of modal class

Question 7

Range

Answer 7

Highest value - Lowest Value

Question 8

Variance

Answer 8

Σxi^2/n -(Σxi/n)^2

Question 9

Mean Square Deviation(s^2)

Answer 9

Σ(xi-a)^2/n