Question

Find arithmetic mean of the following distribution

(i) 

x	19	21	23	25	27	29	31
f	13	15	16	18	16	15	13

(ii) 

x	1	2	3	4	5	6
f	45	25	19	8	2	1

Answer 1

(i)

Arithmetic mean (\(\overline { x }\)) = \(\frac { { \Sigma f }_{ i }{ x }_{ i } }{ { \Sigma f }_{ i } } =\frac { 2650 }{ 106 } \) = 25

Thus, arithmetic mean = 25

(ii)

Arithmetic mean (\(\overline { x }\)) = \(\frac { { \Sigma f }_{ i }{ x }_{ i } }{ { \Sigma f }_{ i } } =\frac { 200 }{ 100 } \) = 2

Thus, arithmetic mean = 2