For the mid values 30, 39, 48, 57 and 66 the second class of the distribution is ________.

Question

Question

This question was previously asked in

SSC CGL Tier-II ( JSO ) 2017 Official Paper ( Held On : 22 Feb 2018 )

Answer 1

Given

Mid values = 30, 39, 48, 57, 66

Formula used

Mid value of class interval = (L₁ + L₂)/2

L₁ = Lower limit

L₂ = Upper limit

Calculation

For Second class mid value would be (L₁ + L₂)/2

Here L₁ and L₂ are Lower value and upper value of class interval

Mid point of 30 and 39 = (L₁ + L₂)/2

⇒ (30 + 39)/2 = 34.5

⇒ Mid point of 39 and 48

⇒ (39 + 48)/2 = 43.5

⇒ Lower limit (L₁ = 34.5)

⇒ Upper limit (L₂ = 43.5)

∴ The second class of this distribution is 34.5 – 43.5

Shortcut Trick

By options

1 – 34 – 44

Class size 44 – 34 = 10

39 – 30 =9

So size gap does not match so option 1 is wrong

2 – 34.5 – 43.5

Class size = 43.5 – 34.5 = 9

The mid point gap

39 – 30 = 9, 48 – 39 = 9, 57 – 48 = 9, and 66 – 57 = 9

So option (2) match with Class Size so option (2) is correct