Question

Mrs. Garg recorded the marks obtained by her students in the following table. She calculated the modal marks of the students of the class as 45. While printing the data, a blank was left. Find the missing frequency in the table given below. Marks Obtained 0 – 20 20 – 40 40 – 60 60 – 80 80 – 100 Number of Students 5 10 – 6 3​

Answer 1

Answer:

12

Step-by-step explanation:

explained in the pictures attached

Answer 2

The missing frequency is 12.

Given:

• Modal marks are 45.
• $\begin{tabular}{|c|c|}\cline{1-2}Marks\:obtained&Number\:of\: student\\\cline{1-2}0-20&5\\\cline{1-2}20-40&10\\\cline{1-2}40-60&x\\\cline{1-2}60-80&6\\\cline{1-2}80-100&3\\\cline{1-2}\end{tabular}$

To find:

• Find the missing frequency.

Solution:

Formula to be used:

$\bf Mode = l + \left( \frac{f1 - f0}{2f1 - f0 - f2} \right) \times h$

here,

f1: frequency of modal class

f0: frequency of preceding class

f2: frequency of succeding class

l: lower limit of modal class

h: height of class

Step 1:

Find modal class and write all the values required for formula.

It is clear that; modal class have highest frequency,but here we don't know one of the frequency.

So, according to the modal marks, it will be decided.

Thus,

40-60 is modal class; because modal marks are 45 which lies in 40-60.

So,

l= 40

f1=x

f0=10

f2=6

h= 20

Mode = 45

Step 2:

Put the values in formula and find x.

$45 = 40+ \left( \frac{x - 10}{2x - 10 - 6} \right) \times 20$

or

$45 - 40 = \left( \frac{x - 10}{2x-16} \right) \times 20$

or

$\cancel 5= \left( \frac{x - 10}{2x-16} \right) \times \cancel{20} \: 4$

or

$1 = \left( \frac{x - 10}{2x-16} \right) \times\: 4$

or

$2x-16 = 4x - 40$

or

$2x - 4x = - 40 +16$

or

$2x =24$

or

$\bf x =12$

Thus,

The missing frequency is 12.

Learn more:

1) The median and mode of the following wage distribution are known to be Rs. 33.5 and Rs. 34 respectively. Three frequ...

https://brainly.in/question/14464263

2) The mode of the following frequency distribution of 165 observations is 34.5. Find the value of a and b.

Class

5-14

14...

https://brainly.in/question/5040836