Statistics

1.The median of a data can graphically be found from

(i) an ogive,

(ii) a histogram,

(iii) a frequency curve,

(iv) a bar graph.

2.The relationship among the three measures of central tendency i.e., median, mode and mean can be represented as

  1. The median of a data is 5. The mean of the same data is 7. Find the mode of the data.
  2. What is the median of a dataset whose mean and mode are 36 and 18 respectively?
  3. The following table shows frequency distributions of a few observations. The mode of the observations is 42. The missing frequency p is not the greatest frequency. Find the value of p?

Class interval

Frequency

  10 – 19

9

  20 – 29

8

  30 – 39

12

  40 – 49

16

  50 – 59

p

  60 – 69

11

  70 – 79

15

  1. The following table lists the frequency distribution of 30 observations. The mean of the data is 48. The value of [f1 − f2] is

       Class interval  0 − 20                  20 − 40          40 – 60           60 – 80               80 – 100

         Frequency (fi)     8                        f1                      6                       4                      f2

 
  1. The following frequency distribution table shows the class marks of continuous class Intervals of 40 observations. What is the median of the given dataset?

Class mark

Frequency

  10

5

  30

7

 50

6

  70

9

  90

6

  110

7

  1. The following data represents a frequency distribution of 90 observations whose median is 125. What is the median of the given data set?

   Height (in cm)

Number of children in locality

   More than 100

  90

   More than 110

   81

   More than 120

   76

   More than 130

   68

   More than 140

   60

   More than 150

   48

   More than 160

   33

   More than 170

   20

   More than 180

    3

  1. What is the median of the given data set? What are the respective values of x and y?
  2.   

    Score

    Frequency

    Less than 30

    Less than 60

    Less than 90

    Less than 120

    Less than 150

    Less than 180

    Less than 210

       7

       15

       27

       27 + x

       36 + x

       36 + x + y

       46 + x + y

       Total

    65

  1. The following data lists the ranges of marks obtained (out of 100) by 60 students of a class. What are the marks scored by more than half of the students?
  2.  

       Marks

    Number of students

        0 – 10

    2

      10 – 20

    1

      20 – 30

    3

      30 – 40

    5

      40 – 50

    7

      50 – 60

    11

      60 – 70

    10

      70 – 80

     9

      80 – 90

     5

      90 – 100

    7

  1. The given frequency distribution table lists the weights of students of two different Grades What is the difference between the modal weights of class IX and X?

Weight(kg)

Number of students in classIX

Number of students in classX

40 – 45
45 – 50
50 – 55
55 – 60
60 – 65
65 – 70

     10
     12
      8
     11
     10
      6

          12
          10
           5
          14
          11
           6                                

Prepared By:
Mr. Vijay Chawla
Email [email protected]
9899114400