Question

The table shows the distribution of the scores obtained by 160 shooters in a shooting competition. Use a graph sheet and draw an ogive for the distribution. (Take 2 cm = 10 scores on the X axis and 2 cm = 20 shooters on the Y-axis).

Scores	0-10	10-20	20-30	30-40	40-50	50-60	60-70	70-80	80-90	90-100
No. of shooters	9	13	20	26	30	22	15	10	8	7

Use your graph to estimate the following: 

(i) The median. 

(ii) The interquartile range. 

(iii) The number of shooters who obtained a score of more than 85%. 

Answer 1

(i) Since, no. of terms, n = 160 which is even

(iii) The number of shooter who obtained a score of more 85%, from E draw a vertical line to meet ogive at F. From F draw a horizontal line to D. 

= 160 – 150 = 10