1 votes 1 votes For the distributions given below: Which of the following is correct for the above distributions? Standard deviation of $A$ is significantly lower than standard deviation of $B$ Standard deviation of $A$ is slightly lower than standard deviation of $B$ Standard deviation of $A$ is same as standard deviation of $B$ Standard deviation of $A$ is significantly higher than standard deviation of $B$ Probability isro-2020 probability standard-deviation normal + – Satbir asked Jan 13, 2020 • edited Apr 10, 2020 by go_editor Satbir 2.1k views answer comment Share Follow See all 2 Comments See all 2 2 Comments reply Krupa Rajani commented Jan 31, 2020 reply Follow Share Can anyone elaborate the maths behind it? 0 votes 0 votes s_dr_13 commented Jan 31, 2020 reply Follow Share https://www.khanacademy.org/math/probability/data-distributions-a1/summarizing-spread-distributions/a/introduction-to-standard-deviation 0 votes 0 votes Please log in or register to add a comment.
3 votes 3 votes Answer: C) Standard deviation of A is the same as the standard deviation of B. This should be answered intuitively from the graph otherwise it would take too much time. Tuhin Dutta answered Jan 13, 2020 Tuhin Dutta comment Share Follow See all 4 Comments See all 4 4 Comments reply akshay7797 commented Jan 16, 2020 reply Follow Share could you please tell how to answer it intuitively? Is it because the difference in height of two consecutive bars same in both graphs? 0 votes 0 votes Tuhin Dutta commented Jan 16, 2020 reply Follow Share Yes, the mean of both graphs is the same and all the deviations are also the same. Thus both equal. 1 votes 1 votes NIKHIL MOLUGU commented Jan 28, 2020 reply Follow Share how are the means same? isnt mean =sigma(value x frequency)/5? 70,110 are the means if calculated in that way. 0 votes 0 votes s_dr_13 commented Jan 31, 2020 reply Follow Share @akshay7797 If you look at the graph carefully,u will notice that the graph has been rotated around 30,and standard deviation does NOT change when graph is been rotated,however note that mean may change if the graph is not symmetrical ( which is true for this example,anyway that's not asked) . Note :- Standard deviation doesn't change when graph is shifted right or left or moved up & down,or rotated around any point. It may change when the graph is sketched or squeezed 1 votes 1 votes Please log in or register to add a comment.
1 votes 1 votes Standard Deviation is the root square of variance,i.e., it depends on how a value varies in the given data. So in the given graph , the varying of data for both the graphs is same , So, the Standard Deviation should be same for both graphs Intekhab Ahmad answered Dec 29, 2021 Intekhab Ahmad comment Share Follow See all 0 reply Please log in or register to add a comment.