a good ppt on stats

2. INTRODUCTION
1.The word “statistics” is used in both its singular and plural
form.
2.In singular sense it is the science of collection, presentation,
analysis, and interpretation of numerical data.
3.In plural sense it means numerical facts or observations
collected with definite purposes.
4. For example, expenditure and income of persons in a
particular locality are statistics.

3. 1.Statistics are expressed quantitavely and not
qualitatively.
2.A single observation doesn't form statistics. It
is a sum of total observation.
3.Statistics are collected with a definite purpose.
4.Statistics in an experiment are comparable and
can be classified into various groups.

4. STATISTICAL DATA
The word data means information. Statistical data’s are of two
types 1.PRIMARY DATA 2.SECONDARY DATA.
Primary Data- When an investigator collects data himself
with a definite plan or design in his/her mind it is primary data.
For example- data in a population census.
Secondary Data- Data which are not originally collected
rather obtained from published or unpublished sources are
secondary data.
For example- literature reviews, case studies.

5. Frequency distribution is a method to present raw
data in the form which one can easily understand
the information contained in the raw data.
Discrete Frequency Table- It is constructed from
the given data by the use of the method of tally
marks.
Grouped Frequency Table- A frequency
distribution is table that categorizes scores by
intervals.

6. Grouped Frequency Table
Discrete Frequency Table

7. STATISTICAL GRAPHS
One goal of statistics is to present data in a meaningful
way. It's one thing to see a list of data on a page, it's
another to understand the trends and details of the data.
1.BAR GRAPHS- It is a pictorial representation of the
numerical data by a number of rectangular bars of uniform
width erected vertically or horizontally with equal spacing
between them.
Each bar represents one numerical data.
The height and length of bars are corresponding to the
numerical data.

8. title
Data on y-
axis
Data on x- axis
bar
scale

9. HISTOGRAM-1.A histogram is a representation of frequency
distribution in the form of rectangles.
2.A histogram is made with the help of class intervals.
3.Bases and heights are corresponding to frequencies. There is
no gap between two rectangles.
Data on y-
axis
title
Data on x- axis
bar
scale

10. FREQUENCY POLYGON-1. A frequency polygon shows a
frequency distribution emphasizing the overall pattern in the
data.
2. It is constructed from a histogram. The frequency polygon
is a polygon - a closed two-dimensional figure of straight line
segments - joining the mid points of the top of the bars
histogm.
title
Data on y-
axis scale
Data on x- axis

11. MEAN, MODE AND MEDIAN
MEDIAN- Median of a distribution is the value of the
variable which divides the distribution into two equal parts.
In other ways it is the middle most value.
If ‘n’is an odd number then the value of median= (n+1)/2
If ‘n’ is an even number then the value of median= [(n/2) or
(n/2+1

12. MODE-It is the most frequently occurring observation.
MEAN-It is simply the average of all the observations.
It is calculated by adding all the values of observation and
dividing it by the total number of observations.
x = {x1+x2……….xn/} No. of observations

13. THANK YOU
MADE BY : AKSHIT GOEL AND RISHABH
GARG