Question

Solve the following :

Calculate D₇ for the following data.

Profit (in crores ₹)	10-20	20-30	30-40	40-50	50-60	60-70
No. of firms	20	30	70	48	32	50

Answer 1

Profit (in crores ₹)	No. of firms	cf
10 - 20	20	20
20 - 30	30	50
30 - 40	70	120
40 - 50	48	168
50 - 60	32	200
60 - 70	50	250
	N = 250

D₇ = Size of 7`(n/10)^"th observation"`

= Size of 7`(250/10)^"th observation"`

= Size of 7`(25)^"th observation"`

= Size of `175^"th observation"`

Hence, decile class = 50-60

L = 50, F = 32, cf = 168, N = 250, H = 10

D₇ = `1 + (((7n)/10-cf))/fxxh`

D₇ = `50+(((7(250))/10-168))/32xx10`

D₇ = `50+(((1750)/10-168))/32xx10`

D₇ = `50+((175-168))/32xx10`

D₇ = `50+(7)/32xx10`

D₇ = `50+(70)/32`

D₇ = 50 + 2.1875

D₇ = 52.19