Calculate the coefficient of range for the following data:
Heights in cm. $120 - 124$ $125 - 129$ $130 - 134$ $135 - 139$ $140 - 144$
No. of students $6$ $9$ $10$ $12$ $8$

Open in App

Solution

First let us find the limits of heights (limits of class intervals) and their mid points.
Height Height limits Midpoint of heights No. of students
$120 - 124$ $119.5 - 124.5$ $122$ $6$
$125 - 129$ $124.5 - 129.5$ $127$ $9$
$130 - 134$ $129.5 - 134.5$ $132$ $10$
$135 - 139$ $134.5 - 139.5$ $137$ $12$
$140 - 144$ $139.5 - 144.5$ $142$ $8$
Upper limit of the highest height, $H = 144.5$ , lower limit of the lowest height, $L = 119.5$ .
Coefficient of range $= \frac{H - L}{H + L} = \frac{144.5 - 119.5}{144.5 + 119.5} = \frac{25}{264} = 0.095$ .

Suggest Corrections

Similar questions

Class Intervals	$110 - 119$	$120 - 129$	$130 - 139$	$140 - 149$	$150 - 159$	$160 - 169$
Frequency	$6$	$8$	$15$	$10$	$6$	$5$

The table below shows the number of students in class 10 of a school, classified according to their heights:

Height

(cm)

Number of Students

120 − 125

125 − 130

130 − 135

135 − 140

140 − 145

145 − 150

150 − 155

155 − 160

Calculate the mean height

100

I.Q.	$55 - 64$	$65 - 74$	$75 - 84$	$85 - 94$	$95 - 104$	$105 - 114$	$115 - 124$	$125 - 134$	$135 - 144$
No. of students	$1$	$2$	$9$	$22$	$33$	$22$	$8$	$2$	$1$

Length(cm)	$120 - 125$	$125 - 130$	$130 - 135$	$135 - 140$	$140 - 145$	$145 - 150$
Number of plants	$8$	$10$	Y	$16$	$8$	$12$

The mean length of the plants is $136$ cm. Find y in the table.

Income (₹)	:	50	70	80	90	100	120	130	150
No of workers	:	2	8	12	7	4	3	8	6

Join BYJU'S Learning Program

Heights in cm.	$120 - 124$	$125 - 129$	$130 - 134$	$135 - 139$	$140 - 144$
No. of students	$6$	$9$	$10$	$12$	$8$