निम्न आँकड़ों का माध्य, प्रसरण व मानक विचलन ज्ञात करो।
`{:("वर्ग ",30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 90-100),(f_(i)""," 3", " 7"," 12"," 15"," 8"," 3"," 2"):}`

Answer

62, 201, 14.8