Question

A grouped frequency table with class intervals of equal sizes using 250 – 270 (270 not included in this interval) as one of the class interval is constructed for the following data:

268, 220, 368, 258, 242, 310, 272, 342, 310, 290, 300, 320, 319, 304, 402, 318, 406, 292, 354, 278, 210, 240, 330, 316, 406, 215, 258, 236.

The frequency of the class 310 – 330 is:

विकल्प

• 4

• 5

• 6

• 7

Answer 1

6

Explanation: 

Here, the lowest value of observation = 210 and the highest value of observation = 406. 

So, class intervals are 210 – 230, 230 – 250, ...., 390 – 410. 

The required frequency distribution table is

Class interval	Tally marks	Frequency
210 – 230	|||	3
230 – 250	|||	3
250 – 270	|||	3
270 – 290	||	2
290 – 310	||||	4
310 – 330	`cancel(||||)|`	6
330 – 350	||	2
350 – 370	||	2
370 – 390	—	0
390 – 410	|||	3

Hence, the frequency of the class 310 – 330 is 6.