Question

The frequency distribution of weights (in kg) of 40 persons is given below.

Answer 1

Answer: (a) 4

(b) 5

(c) 14

(d)

Class interval       Class mark

30 - 35                       $\dfrac{35+30}{2}=32.5$

35 - 40                       $\dfrac{35+40}{2}=37.5$

40 - 45                        $\dfrac{40+45}{2}=42.5$

45 - 50                        $\dfrac{45+50}{2}=47.5$

50 - 55                        $\dfrac{50+55}{2}=52.5$

Step-by-step explanation:

The data of 40 persons is given as :

Weights (in kg)    Frequency

30 - 35                  6

35 - 40                   13

40 - 45                   14

45 - 50                   4

50 - 55                  3

(a)

Lower limit is the lowest number in a class interval .

So, is the lower limit of fourth-class interval (45 - 50) is 4.

(b)

Class size = Upper limit - lower limit

So, Class size of first class interval = 35-30=5

Thus , class size of each interval is 5. [ class size remains same]

(c)

Highest frequency in table = 14 which is corresponding to 40 - 45   .

Thus , 40 - 45  is the class interval has the highest frequency.

(d)

Class mark is the mid value of each class interval.

Class interval = $\dfrac{(\text{Upper limit+Lower limit})}{2}$

Class interval       Class mark

30 - 35                       $\dfrac{35+30}{2}=32.5$

35 - 40                       $\dfrac{35+40}{2}=37.5$

40 - 45                        $\dfrac{40+45}{2}=42.5$

45 - 50                        $\dfrac{45+50}{2}=47.5$

50 - 55                        $\dfrac{50+55}{2}=52.5$