The frequency distribution of weights (in kg) of 40 persons is given below. Weights (in kg)
30 - 35
35 - 40
40 - 45
45 - 50
50 - 55
Frequency
6
13
14
4
3
(a) What is the lower limit of fourth-class interval?
(b) What is the class size of each class interval?
(c ) Which class interval has the highest frequency?
(d) Find the class marks of all the class intervals?

(a) 4

(b) 5

(c) 14

(d)

Class interval       Class mark

30 - 35                      

35 - 40                      

40 - 45                        

45 - 50                        

50 - 55                        

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 =

Class interval       Class mark

30 - 35                      

35 - 40                      

40 - 45                        

45 - 50                        

50 - 55                        

step-by-step explanation:

given that there are two triangles j'k'l' and jkl>

the former is got by dilating the second one.

when drawn on a grid, (graph paper) coordinates of vertices of first triangle is

(6,12)j, (9,6)k and (12,9)l

side jk has length = distance between j and k

=

side j'k'=distance between j' and k'

=

ie j'k'l' has sides 1/3 of that of corresponding sides of jkl.

hence scale factor of 1/3 is used to get j'k'l'from jkl