RESEARCH METHODOLOGY

METHODS OF DATA ANALYSIS

MEASURES OF DISPERSION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Suppose you have 3 data values of 12, 14, and 16. If a value of 30 is added to the data set, what effect does this have on the mean and standard deviation?
A
The mean and standard deviation will not change.
B
The mean will increase, but the standard deviation will not change.
C
Both the mean and standard deviation will increase.
D
The mean will stay the same, but the standard deviation will increase.
Explanation: 

Detailed explanation-1: -The correct answer is: it will increase by 10.

Detailed explanation-2: -Answer: No change in variance if each number increase by 4. So variance = Square(SD) = 3*3 = 9.

Detailed explanation-3: -The ‘’˜measure of spread’ will change. If every term is doubled, the distance between each term and the mean doubles, BUT also the distance between each term doubles and thus standard deviation increases.

There is 1 question to complete.