st095 ยป

Summary of Lesson 3

Just like in our daily life there are different adjectives to describe the characteristics of a person, in statistics there are different words used to describe a dataset which help us characterize it. This lesson introduces and explains a few such statistical terms.

Mean : is simply the average of all the data points.
Median : if all the data points are arranged in ascending order (or descending order), the median is simply the data point in the middle of the newly arranged dataset.
Mode : is the data point which occurs with the highest frequency in the dataset.

Eg. : if the dataset is - 2,6,3,5,1,9,4,3,4,3; then
mean = (2+6+3+5+1+9+4+3+4+3)/10 = 40/10 = 4

median - arrange dataset in ascending order 1,2,3,3,3,4,4,5,6,9 median is (3+4)/2 = 3.5

mode is the point with highest frequency, which is 3

Here is a good wikipedia article which compares mean, median and mode.

uniform distribution
is a distribution which has no mode, in other words we can say that if we draw a graph of such a distribution, all points will occur at the same frequency of 1.