Question

the class mark of a particular class- interval is 8.5 and class size is 3. find the class interval

Answer 1

Class size is 3 n class mark is 8.5 i.e. D mid no. We need 1 no. Before d mid value n 1 after dat. Therefore we need 2 nos. so we will divide 3 by 2 n we will get 3/2 = 1.5. We will subtract 1.5 from 8.5 to get no. Before it...so it is 8.5 - 1.5 = 7 n now we need 1 no. After it so we will add 1.5 to 8.5 that will be 1.5 + 8.5= 10. So d class interval is 7 - 10 . U can check that d class size is 3 That is 10 - 7 = 3 n class mark is (10 + 7)/2 = 17/2 =8.5 that proves that 7 - 10 is the correct class interval.