46 student of class obtain a following mark in statistics in weekly
test
marks
9
10
11
12
13
14
15
16
17
18
no of student
1
2
3
6
10
11
7
3
2
1
calculate the arithematic mean
using Direct Method
Answers
Answer:
In the study of a population with respect to one in which we are interested we may get a large number of observations. It is not possible to grasp any idea about the characteristic when we look at all the observations. So it is better to get one number for one group. That number must be a good representative one for all the observations to give a clear picture of that characteristic. Such representative number can be a central value for all these observations. This central value is called a measure of central tendency or an average or a measure of locations. There are five averages. Among them mean, median and mode are called simple averages and the other two averages geometric mean and harmonic mean are called special averages.
Arithmetic mean or mean
Arithmetic mean or simply the mean of a variable is defined as the sum of the observations divided by the number of observations. It is denoted by the symbol If the variable x assumes n values x1, x2 … xn t