Monday, May 14, 2012

Statistic RKUD 3910 Notes

As mentioned in previous post that I will continued my work on my Basic Introduction to Statistical Study, but because of my laziness, I decided to make a basic notes about it first, as examination for most Higher Level of Education in Malaysia are just in the corner, especially IIUM. There for, for those who are taking RKUD 3910  can benefit from this. Take note that you still need to read, study and practice, not just depend on this note. On this note there are some missing character as it cannot be paste on this blog, there for if you want the note(which have the picture/character of the equation etc.), feel free to ask by email to

Reference for Descriptive Statistic:
100% = All
80% = Majority
75% = Three-quarter
65% = Two-thirds
50% = Half
33% = One-third
20% = One-fifth
10% = Minority/One-tenth
0% = Nill/None

 Value (+/-):
0.0      – 0.20 = very weak relationship
0.21– 0.40 = weak relationship
0.41– 0.60 = moderate
0.61– 0.80 = strong relationship
0.81 – 1.00 = very strong relationship
            X         Y

Central Tendencies
MODE = the highest frequency
MEDIAN = arrange form the smallest to the biggest, and then take the middle no. Example:
                        1          2          2          4          5          7          7
Number 4 is the median. But if there are two numbers instead of one, both numbers should be plus or add and then divide by two, for example:
1          2          2          3          4          4          5          6          7          8          8          9
=          4+5=9.             9÷2=4.5
There for the MEDIAN are 4.5
MEAN =            or an average score of the total

Indices of Dispersion
Standard Deviation:


Correlation (relationship) =
Slope (b): If we control x, what is y?
        • = 13+b=?

Intercept (a): To find a if x=0

Equation of Straight Line:
To find y =      y = a + bx
To find x =      a = bx = y
                   bx = y – a
                   x =

Reminder to make as below to ease your calculation:
r =? ,        =?     =?    =?    N=?         =?      =?    =?         =?          SDy=?     SDx=?


Statistic: A set of mathematical method for organizing, summarizing and interpreting method.
Tally System: classical way to collect data, to count or measure the variable.
1.     Descriptive Statistic: are statistical methods that are use to organizing, summarizing and simplify the data to describe the population.
2.     Inferential/Corollation Statistic: are techniques that allowed us to study samples and then make generalizations about the populations.
1.     Constant: a characteristic or condition that does not vary but is the same for every person.
2.     Variables: a characteristic or condition that changes or has different values between one another.
Independent Variables: is the variable that is manipulated by researchers and assume as the cause.
Dependent Variables: Is the variable there is observe for changes in order to access the effect of the treatment.
Corrolation: Observation over 2 types of variables regarding their relationship.
Multiple Variables: The observation of relationship between IV and DV where both of them may consist more than one variable.


1.     Nominal: is a set of categorize that are indicated by different names according to their particular characteristics. Example: Gender, race, etc.

2.     Ordinal: is a set of categorizes that are organized in an order sequence. For example from high to low, level of studies, etc.

3.     Interval: is a set of one ordered categories where each categorize is set with certain values. Example: range 3 to 30, etc.

1.     One sample T-Test: Testing a variable with a Test Score.

2.     Independent T-Test: Comparing two categories with a variable.

3.     Paired T-Test: Comparison of two separate variables.