Two distributions with 100 and 200 items have a mean of 20 and 10. Find the combined mean of two distributions.
{ N }_{ 1 } = 100
and { \bar { X } }_{ 1 } = 20
.’. Total value of Distribution 1 = \{ N } _{ 1 }\times\ \overline { X } _{ 1 }
= 100 x 20 = 2000
\{ N } _{ 2 }\times \overline { X } _{ 2 } = 10
Total value of Distribution 2 = \{ N } _{ 2 }\times \overline { X } _{ 2 }
= 200 x 10 = 2000
