Find the mean of the marks obtained by 30 students of Class IX of a school, 10 20 36 92 95 40 50 56 60 70 92 88 80 70 72 70 36 40 36 40 92 40 50 50 56 60 70 60 60 88

Explanation

We know,

`Mean = `Sum of all observations`/`Total number of observations

Here, Sum of all observations ` = 10 + 20+ 36+ 92+ 95 +40`
`+ 50+ 56+ 60+ 70+92+ 88+ 80 +70+ 72+ 70`
`+36+ 40+ 36 +40+92+ 40+ 50+ 50+ 56+ 60+ 70 +60+ 60+ 88= 1779`

Total number of observations `=30`

So, `Mean = 1779/30 = 59.3`