Question

The following is the distribution of weights (in kg) of 52 persons:

Weight in kg	Persons
30-40	10
40-50	15
50-60	17
60-70	6
70-80	4

(i) What is the lower limit of class 50-60?
(ii) Find the class marks of the classes 40-50, 50-60.
(iii) What is the class size? 

Answer 1

(i) The lower limit of the class 50\[-\]60 is 50.

(ii) Class mark for the class 40\[-\]50: 

\[\frac{40 + 50}{2}\]
\[ = \frac{90}{2}\]
\[ = 45\]

Again, class mark for the class 50 \[-\] 60:

\[\frac{50 + 60}{2}\]
\[ = \frac{110}{2}\]
\[ = 55\]

(iii) Here the class size is  40\[-\] 30, i.e. 10.