Question

Find the arithmetic mean for the following frequency distribution .

x	5	10	15	20	25	30	35	40	45	50
f	20	43	75	67	72	45	39	9	8	6

Answer 1

$x5101520253035404550$

$f20437567724539986$

$\sum fx=(5\times 20)+(10\times 43)+(15\times 75)+(20\times 67)+(25\times 72)+(30\times 45)+(35\times 39)+(40\times 9)+(45\times 8)+(50\times 6)=8530$

$\sum x=5+10+15+20+25+30+35+40+45+50=275$

$Mean=\frac{\sum fx}{\sum x}=\frac{8530}{275}=31.01$