Forty persons were examined for their Haemoglobin % in blood (in mg per 100 ml) and the results were grouped as below: Find Mode. Haemoglobin % (mg/100ml) 13.1 – 14 14.1 – 15 15.1 – 16 16.1 – 17 17.1 – 18 No. Of persons 8 12 10 6 4

Haemoglobin % (mg/100ml)	Class boundaries	No. of persons Frequency (f)
13.1 – 14	13.05 – 14.05	8
14.1  - 15	14.05 – 15.05	12
15.1 – 16	15.05 – 16.05	10
16.01 – 17	16.05 – 17.05	6
17.1 – 18	17.05 – 18.05	4

Here, the maximum frequency is 12 corresponding to class boundary 140.5 – 15.05

∴ f_m = 12, f₁ = 8, f₂ = 10, h = 1 and L = 14.05

Mode	=	L	+	fm	-	f1			h
				2fm	-	f1	-	f2

Mode	=	14.05	+	12	-	8			1
				2(12)	-	8	-	10

Mode	=	14.05	+		4
					6

Mode = 14.72 mg/ 100 ml.