keats wrote:
I have a question regarding standard deviation. I am unsure about how to solve standard deviation's comparing sets questions. For example: If I am given a set and asked as to what of the following options have the standard deviation closest to the one given in question. Questions such as
Which of the following options have the standard deviation closest to the standard deviation to set A = [10,15,20,25,30]
A [30,40,50,60,70]
B [5,15,25,35,45]
C [20, 35, 50, 65, 80]
D [ -20,-10,0,10,20]
E [24, 40, 56, 80,96]
How do I compare these options with the one given in the question?
Hi
keats,
In the set A gap between consecutive terms is 5. Now, check for all the options.
(A) Gap 10
(B) Gap 10
(C) Gap 15
(D) Gap 10
(E) Gap 16,16,24, and 16.
There is no unique answer to this question. Option (A), (B) and (D) will have closest Standard Deviation (SD) to the Set A.
You don't need to compute the SD for all the options.
Some more information we can deduce from the above-given data set without computing SD.
=> Option (A), (B), and (D) will have the same SD. Because SD doesn't change with addition or subtraction of a constant number.
=> Option (E) will have highest SD among all.
Hope this helps.