Question

The following is the frequency distribution.
of
Marks
0-20 20-40 40-60 60-80
Number of students 19
a 40 b 15
Total: 100
The value of b is twice the value of a
Find their values and draw a histogram.​

Answer 1

The value of a is 12 and b is 24.

Given,

         Total = 100

9 + a + 40 + b + 15 = 100

          b = 2a

64 + a + 2a = 100

              3a = 100 - 64

              3a = 36

                a = 12

                b = 2a

                b = 24

   Marks                Number of students

  0 - 20                               9

 20 - 40                              12

 40 - 60                              40

 60 - 80                              24

80 - 100                              15                                          

 

Answer 2

Value of a = 12 and value of b = 24

Step-by-step explanation:

The following table is given the marks obtained by the students.

Total number of students = 100

Therefore, 9 + a + 40 + b + 15 = 100 -----------(1)

As per given statement the value of b is twice the value of a.

Hence, b = 2a

Now put the value of b in the equation (1)

9 + a + 40 + 2a + 15 = 100

a + 2a = 100 - 9 - 40 - 15

3a = 36

a = 12

b = 2(12) = 24

Value of a = 12 and value of b = 24

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