Ex 14.2, 6 - Chapter 14 Class 10 Statistics

Transcript

Ex 14.2, 6 A student noted the number of cars passing through a spot on a road for 100 periods each of 3 minutes and summarised it in the table given below. Find the mode of the data: Number of cars Frequency 0 – 10 7 10 – 20 14 20 – 30 13 30 – 40 12 40 – 50 20 50 – 60 11 60 – 70 15 Mode = l + (𝑓1 −𝑓0)/(2𝑓1 −𝑓0 −𝑓2) × h Modal class = Interval with highest frequency = 40 – 50 where l = lower limit of modal class = 40 h = class-interval = 10 - 0 = 10 f1 = frequency of the modal class = 20 f0 = frequency of class before modal class = 12 f2 = frequency of class after modal class = 11 Mode = l + (𝑓1 −𝑓0)/(2𝑓1 −𝑓0 −𝑓2) × h = 40 + (20 −12)/(2(20)−12−11) × 10 = 40 + 8/(40 −23) × 10 = 40 + 80/17 = 40 + 4.7 = 44.7