The class size of distribution is 25 and the first class-interval is 200 - 224. There are seven class-intervals.

Question:

The class size of distribution is 25 and the first class-interval is 200 - 224. There are seven class-intervals.

(i) Write the class-intervals.

(ii) Write the class marks of each interval.

Solution:

Given

Class size = 25

First class interval = 200 - 224

(i) Seven class interval are:

200 - 240, 225 - 249, 250 - 274, 275 - 299, 300 - 324, 325 - 349,3 50 - 374.

(ii) Class mark = 200 - 224

$=\frac{200+224}{2}$

= 424/2

= 212

Class mark = 225 - 249

$=\frac{225+249}{2}$

= 479/2

= 237

Class mark = 250 - 274

$=\frac{250+274}{2}$

= 524/2

= 287

Class mark = 300 - 324

$=\frac{300+324}{2}$

= 624/2

= 312

Class mark = 325 - 349

$=\frac{325+349}{2}$

= 674/2

= 337

Class mark = 350 - 374

$=\frac{350+374}{2}$

= 724/2

= 362

 

 

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