Average is equal to (sum of all numbers)/(count of numbers).

Here count = 12, sum = (85 + 72 + 97 + 81 + 77 + 93 + 100 + 75 + 86 + 70 + 96 + 80) =

(157 + 178 + 170 + 175 + 156 + 176) =

(335 + 345 + 332) = 900 + 100 + 12 = 1012.

So the average is 1012/12 = 253/3 = 84 and 1/3 = 84,3333(3)... or approx. 84.33.

(please ask if you need mode or median or else)

First you want to add up all of the numbers. Your sum will be 1,012. Next, we need to divide the sum by the total number of numbers you added. Therefore it would be 1,012 / 12, which is 84.3.

Average= (sum of quantities)/(no of quantities)``

sum of quantities = 85+72+97+81+77+93+100+75+86+70+96+80

no of quantities=12

Average= (1012)/12 =84.33

Let the given set be `i_(k) =` {85,72,97,81 ,77 ,93,100, 75, 86, 70, 96, 80}

Average of "n" numbers in a set is calculated by = (sum of all **n** numbers)/** n**

** = `(sum_(k=1)^n(i_(k)))/n` **

**Here n=12**

sum of 12 numbers

= 85 + 72 + 97 + 81 + 77 + 93 + 100 + 75 + 86 + 70 + 96 + 80

= 1012

Now average is

Average of these 12 numbers = ` (sum_(k=1)^n(i_(k)))/n `

`=1012/12`

`= 84.3333 =84.34 `

``