निम्नलिखित बंटन के लिए माध्य , प्रसरण तथा मानक विचलन ज्ञात कीजिए :
`{:("वर्ग",30-40,40-50,50-60,60-70,70-80,80-90,90-100),("बारम्बारता"," "3," "7," "12," "15," "8," "3," "2):}`

Explanation

`:. ` माध्य , ` barx = (sum f_(i)x_(i))/(sum f_(i))`

` = (3100)/50 = 62`

प्रसरण , ` sigma ^(2) = (sum f_(i)(x_(i)-barx)^(2))/(sum f_(i)) `

`= 10050/50`

` = 201`.

और मानक विचलन , ` sigma = sqrt(201) = 14.18`.