Reseacrch Methodology and Biostatistics [STM315]. class one.

Revision on introduction to Statistics.

Statistics is a science that deals with techniques used in collection, compilation, analysis, summarization, presentation of numerical facts [data], for the purpose of making decisions in the midst of uncertainty [future].

There are several branches of statistics...

Mean for ungrounded data

x_bar is also written as x in this work.

× = Σx₁/n

Where n= number of variables. 

E.g. if we have five variables.

    5, 8, 10, 6, 7.

The mean becomes;

x= 5+8+10+6+7/5 

x= 36/5 = 7.2 Approximately. 

Variance [s²] = Σ(x₁ -x)² /n

Let's have our variable table drawn for the parameters. 

X                 (x₁-x)²

5                 4.84

8                 0.64

10              7.84

6                1.44

7                0.04

   Σ(x₁-x)² 14.8

Variance = S²

S² = 14.8/5

S² = 2.96

Standard Deviation = √variance

                             S = √2.96

                             S= 1.72

                             Data

Data is a raw fact or an unprocessed information while;

Information is a processed data.

      Methods of obtaining data

1. Primary data 

2. Secondary data.

       1. Primary data: they are collected from the source for the first time by a researcher for a particular purpose, and its been used only for that purpose.

There are several ways of collecting primary data which are;

i. Direct observation 

ii. Interview

iii. Questionnaire 

iv. Experimental method.

      2. Secondary data: they are by-product of primary data, most web data are secondary data.

      There are several ways of getting secondary data which are;

i. Through the internet

ii. Through social media

iii. Through journals and publications 

iv. Economic data is gotten from the Central Bank

v. Biological data is gotten from the hospital and medical centres.