MADAM SITI AISYAH BINTI ZAKARIA INSTITUT MATEMATIK KEJURUTERAAN UNIVERSITI MALAYSIA PERLIS.
-
Upload
rosa-pierce -
Category
Documents
-
view
216 -
download
0
Transcript of MADAM SITI AISYAH BINTI ZAKARIA INSTITUT MATEMATIK KEJURUTERAAN UNIVERSITI MALAYSIA PERLIS.
MADAM SITI AISYAH BINTI ZAKARIA
INSTITUT MATEMATIK KEJURUTERAANUNIVERSITI MALAYSIA PERLIS
Students, like professional people, must be able to read and understand the various statistical studies performed in their fields. To have this understanding, they must be knowledgeable about the vocabulary, symbols, concepts, and statistical procedures used in these studies.
Students and professional people may be called on to conduct research in their fields, since statistical procedures are the basic to research. To accomplish this, they must be able to design experiments; collect, organize, analyze, and summarize data; and possibly make reliable predictions or forecasts for future use. They must also be able to communicate the results of the study in their own words.
Students and professional people can also use the knowledge gained from studying statistics to become better consumers and citizens. For ex. They can make intelligent decisions about what products to purchase based on consumer studies about government spending based on utilization studies and so on.
2MADAM SITI AISYAH BINTI ZAKARIA
3MADAM SITI AISYAH BINTI ZAKARIA
Examples statements present some statistics in business:
• Bill Gates is the richest American with a net worth $43 billion (Forbes, September,30,2002).
• A total of 35billion transactions were handled by the Visa system during 2001 (Forbes, September 16,2002).
• On average, a household carried a credit card balance in $8562 in 2001 (Newsweek, April 1, 2002).
• On average, a wedding in America costs $20,357 (Smart Money, June 2002).
• Based on the 2000 census, 40.5 million households have two vehicles. (Source: Census Bureau)
4MADAM SITI AISYAH BINTI ZAKARIA
DATA Data is the facts and figures collected, analyzed, and
summarized for presentation and interpretation A data with lot of observations usually looks non informative
that is we cannot get much information with the raw data. Raw data is also called as ungrouped data. Data refers to quantitative or qualitative attributes of a
variable or set of variables.
- Example :- the whole numbers that represents the scores of students.
Data is categorized by two :-
- quantitative data
- qualitative data Data should be summarized in more informative way such as
graphical, diagrams and charts.
5MADAM SITI AISYAH BINTI ZAKARIA
Element – entities on which data are collected ( ex. In note)
Variable – is a characteristic of interest for the elements
Observation – the set of measurements obtained for a particular element
MADAM SITI AISYAH BINTI ZAKARIA 6
Measurement Levels and the Appropriate Averages
ALL DATA
Qualitative data Quantitative data
Nominal
Car makes,Days of Week,Gender
Ordinal
TV channelRanks and titleCalendar dates
Interval and Ratio
Sales ($)Accounts Receivable
Market share
Mode Median Mean
7MADAM SITI AISYAH BINTI ZAKARIA
There are four measurement scales :-
i. Nominal
ii. Ordinal
iii. Interval
iv. Ratio
1) Nominal only for qualitative classification. the weakest data measurement where numbers are used to
represent an item / characteristic. each data should not be treated as numerical since relative size
has no meaning. no order or ranking can be imposed on the data.
(e.g : gender – male =1 , female = 2)8MADAM SITI AISYAH BINTI ZAKARIA
2) Ordinal it is possible to rank order all the categories according to some
criterion. classifies data into categories that can be ranked ( no precise
difference )
(e.g : grades – A,B,C,D and collegiate class – freshman, sophomore, junior, senior)
3) Interval have the property that the distances between categories are
defined by fixed and equal units. is ranks of data quantity and compare the size of difference between two
observations (precise difference do exist)
(example :For age, a change from age 21 to 22 is the same for changes age 31 to 42)
9MADAM SITI AISYAH BINTI ZAKARIA
4) Ratio The highest level of measurement and allows for all basic
arithmetic operations including division and multiplication. Has the property that a zero point is naturally defined. The mode, mean, median can be used to describe interval and
ratio data. Poses all the characteristics of interval measurement. True zero exist.
(E.g : Production of 20 units per hour (ratio level) is twice the production of 10 units per hour)
10MADAM SITI AISYAH BINTI ZAKARIA
Variable
Quantitative Qualitative
Discrete(e.g, number of houses,
cars accidents
Continuous (e.g., length, age, height, weight, time) e.g., gender,
marital status
11MADAM SITI AISYAH BINTI ZAKARIA
1) Quantitative variable A variable that can be measured numerically. Data collected on a quantitative variable are called quantitative data. There are two types of quantitative variables:-
i. Discrete Variable
A variable whose values are countable, can assume only
certain values with no intermediate values.
ii. Continuous Variable
A variable that can assume any numerical value over a
certain interval or intervals.
2) Qualitative variable A variable that cannot assume a numerical value but can be classified into
two or more nonnumeric categories. Data collected on such a variable are called qualitative data.
12MADAM SITI AISYAH BINTI ZAKARIA
1) Cross Section Data Data collected on different elements at the same point in time
or for same period of time. An example of cross-section data which is giving of six
companies for the same period (2007) :-
Company 2007 Charitable Giving (millions of
dollars)
Home Depot 42
Macy`s 35.2
Wal-Mart 337.9
Best Buy 31.8
Target 168.9
Lowe`s 27.5Table 1.2 : Charitable Givings of Six Retailers in 2007
13MADAM SITI AISYAH BINTI ZAKARIA
2) Time-Series Data Data collected on the same element for the same variable at
different points in time or for different periods of time. Example, a Movieplex with 8 screens would count as 8 toward
the total number of screens.
Year Total Indoor Movie Screens
2003 35,361
2004 36,012
2005 37,092
2006 37,776
2007 38,159
2008 38,198
Table 1.3 : Number of Movie Screens
14MADAM SITI AISYAH BINTI ZAKARIA
DATA SOURCES
SOURCES OF DATA
Primary Data(data collected
by the researcher)
Examples:-i.Personal Interviewii.Telephone Interviewiii.Questionnaireiv.Observations
Secondary Data(already collected/
published by someone else)
Examples:- From books, magazines,
annual report, internet
15MADAM SITI AISYAH BINTI ZAKARIA
STATISTICS Numerical facts Field or discipline of study Collection of methods for planning experiments,
obtaining data and organizing, analyzing, interpreting and drawing the conclusions or making a decision.
Example : (In NOTE)
16MADAM SITI AISYAH BINTI ZAKARIA
STATISTICS
DESCRIPTIVE STATISTICS
DESCRIPTIVE STATISTICS
INFERENTIAL STATISTICS
INFERENTIAL STATISTICS
Using tables, graphs & summarymeasures
Using sample result inmaking decision or predict about a population.
Also called inductive reasoning or inductive statistics.
17MADAM SITI AISYAH BINTI ZAKARIA
Descriptive Statistics
a study on data summary or describes a collection, data organization (presentation of data in a more informative way such as graphical, diagrams and charts).
In general divided by two categories :-
- Data presentation (display)
- Tabular
- Charts/graphs
- Statistics
18MADAM SITI AISYAH BINTI ZAKARIA
Inferential Statistics Consists of generalizing from samples to population,
performing estimations and hypothesis tests, determining relationships among variables, and making predictions.
Area statistics which are deal with decision making procedures.
Population – consists of all subjects (human or otherwise) that are being studied.
Sample – is a group of subjects selected from a population.
Example :-
- In order to find the salary of a college graduate, we may select 2000 recent college graduates, find the starting salaries and make decision based on the information.
19MADAM SITI AISYAH BINTI ZAKARIA
STATISTICAL ANALYSIS USING EXCEL
Example 1.1 :-
Following table shows data for income tax returns for 1995 to 2001 that were filed electronically. Get the sum of income tax for all years and get average of the income tax for those 7 years.
i. Data is key in using Excel.
Figure 1
20MADAM SITI AISYAH BINTI ZAKARIA
ii. To get sum of income tax for all years, type =SUM(.
iii. Select the range of cells (C4:C10) of numerical data, and close the bracket.
Figure 2
21MADAM SITI AISYAH BINTI ZAKARIA
iv. Press Enter, the sum should appear.
Figure 3
22MADAM SITI AISYAH BINTI ZAKARIA
v. To get, the average, the sum should divide by the number of
years.
vi. Type =AVERAGE(.
vii. Select the range of cells for all years (C4:C10) and close bracket.
viii. Press Enter. The average of income tax for those years should appear.
Figure 4
23MADAM SITI AISYAH BINTI ZAKARIA
Population- Entire collection of individuals which are characteristic
being studied.
Sample
- Subset of population.
Population
Sample
24MADAM SITI AISYAH BINTI ZAKARIA
Census - Survey includes every member of population.
Sample survey- Collecting information from a portion of population (techniques)
Element
- Specific subject or object about which information collected.
Variable- Characteristics which make different values.
25MADAM SITI AISYAH BINTI ZAKARIA
Observation
- Value of variable for an element.
Data Set
- A collection of observation on one or more variables.
Name Score
Mohd Amirul bin Hamdi
90
Hashimah 78
Element
Variable
Observation/Measurement
Table 1: Student’s Score for Business Statistic
26MADAM SITI AISYAH BINTI ZAKARIA
MADAM SITI AISYAH BINTI ZAKARIA 27