Question

17 The histogram shows information about the times taken by some students to finish a puzzle. 0.8 0.6 Frequency density 0.4 0.2 10 20 30 50 Time taken (minutes) (a) Complete the frequency table for this information. Time taken ( minutes) Frequency 4 25 < 30 5 30< <50 .) Find ona est extimate ior the lowo finsh the puzzeCouud you answe quatne of the tines taken to flnish puzzle Toku freguency=23 why do ue divi de 23 by 4?

Answer 1

We usually divide the data into four equal parts using 3 points.

First Quartile or Lower Quartile : It is the point below which 25% of the data lies.

Second Quartile or the Median : it is the point below which 50% of the data lies.

Third Quartile or Upper Quartile : it is the point below which 75% of the data lies.

Here total frequency is given as 23

25% of that will be    

25 ×23=-=5.75

so lower quartile position will be at 5.75.