Question

Refer to the attachment​

Answer 1

Answer:

The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count.

The mean, or average, is calculated by adding up the scores and dividing the total by the number of scores. Consider the following number set: 3, 4, 6, 6, 8, 9, 11.

its a defination and formula

apply this and try yourself

Answer 2

Answer:

As we know, the mean is the average of the data. In this question, we need to calculate the mean of grouped data. To calculate mean of grouped data given, we have formula x¯¯¯=∑fixi∑fi . Now, we have to put the values in the formula to get the mean of the given data.

Step-by-step explanation:

Complete step-by-step answer:

We know, mean of the given data is calculated by:

x¯¯¯=∑fixi∑fi

Where,

xi

= mid value of the class interval

fi = frequency of the class

Now, we need to find all the above values in a tabular form.

Class interval Frequency (fi ) Mid value(xi ) fixi

0-10 12 5 60

10-20 16 15 240

20-30 6 25 150

30-40 7 35 245

40-50 9 45 405

Total 50 1100

Now, putting all the values in the above formula

⇒x¯¯¯=∑fixi∑fi⇒x¯¯¯=110050⇒x¯¯¯=22

Therefore, the mean of the given data is 22.

Note: Mean can be calculated by three different methods that are the direct method which is used above, assumed mean method and step-deviation method. Any of the methods can be used to calculate mean.