To increase the mean of 4 numbers by 2, by how much would the sum of the 4 numbers have to increase?

1 Answer
May 21, 2018

#8#

Explanation:

The mean of #4# numbers can be denoted as:

#barx=(sum_(n=1)^4a_n)/4#

When the mean increases by #2#,

#barx+2=(sum_(n=1)^4a_n)/4+2#

Common denominator,

#barx+2=(sum_(n=1)^4a_n+8)/4#

From the above, it is seen that,

#sum_(n=1)^4a_n+8=4(barx+2)#

Hence, to get an increment of #2# in the mean, the sum of the four numbers would have to increase by #8#.