Question

Find the mean of following frequency distribution. Classes:0-20,20-40,40-60,60-80,80-100and frequency is 15,18,21,29,17

Answer 1

Answer:

The mean of the data is 20.

Step-by-step explanation:

Given : The data with classes and their frequency.

To find : The mean of the data ?

Solution :

We create the table of data :

Classes -    0-20      20-40        40-60        60-80       80-100

Frequency-  15             18              21              29               17

The mean of the data is defined as the summation of all the frequency divided by number of frequency.

$Mean = \frac{\sum f_i}{i}$

Total number of frequency i = 5

Summation of frequency is

$\sum f_i=15+18+21+29+17$

$\sum f_i=100$

Substitute in the formula of mean,

$Mean = \frac{100}{5}$

$Mean = 20$

Therefore, The mean of the data is 20.

Answer 2

We create the table of data :

Classes -    0-20      20-40        40-60        60-80       80-100

Frequency-  15             18              21              29               17

The mean of the data is defined as the summation of all the frequency divided by number of frequency.

Mean = \frac{\sum f_i}{i}Mean=i∑fi

Total number of frequency i = 5

Summation of frequency is

\sum f_i=15+18+21+29+17∑fi=15+18+21+29+17

\sum f_i=100∑fi=100

Substitute in the formula of mean,

Mean = \frac{100}{5}Mean=5100

Mean = 20Mean=20

Therefore, The mean of the data is 20.