Notes Revised By Khurram Shamim Khan

NCBMS

Chapter No.3 Mean

Measures of Central Tendency

 

 

l     A statistic is a characteristic or measure obtained by using the data values from a sample.

 

l     A parameter is a characteristic or measure obtained by using the data values from a specific population.

 

The Arithmetic Mean (arithmetic average)

 

 

l     The mean is defined to be the sum of the data values divided by the total number of values.

 

l     We will compute two means: one for the sample and one for a finite population of values.

 

l     The mean, in most cases, is not an actual data value.

 

The Sample Mean

 

 

 

 

 

 

 

 

 

 

 

 

 

The Sample Mean - Example

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The Population Mean

 

 

 

 

 

 

 

 

 

 

 

 

 

The Population Mean – Example

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The Sample Mean for an Ungrouped Frequency Distribution

 

 

 

 

 

 

 

 

 

 

 

 

The Sample Mean for an Ungrouped Frequency Distribution – Example

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The Sample Mean for a Grouped Frequency Distribution

 

 

 

 

 

 

 

 

 

 

 

The Sample Mean for a Grouped  Frequency Distribution – Example