Question

The class size of a 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 intervals.

Answer 1

Since, there are 7 class intervals and first class is 200–224, therefore all the class intervals are:

(i) 200–224

(ii) 225–249

(iii) 250–274

(iv)275–299

(v)300–324

(vi)325–349

(viii)350–374

We know that the class mark corresponding to each class mark is given by:

Now,

Therefore, the class marks are:

212, 237, 262, 287, 312, 337 and 362