Question

1. Suppose you have the following data, with a mean and standard deviation of 5 and 2.1 3 3 4 5 7 8   If you were to subtract 2 from every observation, what change - if any- would you see in the transformed mean and standard deviation?

2. 1. the mean and standard deviation would decrease

   2.   the mean wold stay the same but the standard deviation would decrease

   3.   the mean and standard deviation would stay the same

   4.   the mean would decrease but the standard deviation would stay the same

3. Consider the following data

22 35 50 58 61 69 75

Suppose that we multiply the last three numbers by 5. What effect would this have on the median in the data?

1. increase the value of the median

2.   decrease the value of the median

3.   no effect

Answer 1

1) If you were to subtract 2 from every observation, what change - if any- would you see in the transformed mean and standard deviation?

Ans: the mean would decrease but the standard deviation would stay the same

New Mean =old mean-2

new standard deviation=old standard deviation

	Old Data	New Data=Old Data-2
	5	3
	2.1	0.1
	3	1
	3	1
	4	2
	5	3
	7	5
	8	6
Mean	4.6375	2.6375
StdDev	2.047952	2.047952

2) Consider the following data

22 35 50 58 61 69 75

Suppose that we multiply the last three numbers by 5. What effect would this have on the median in the data?

Ans: no effect

Median is middle most observation in ordered data

here total observations are 7 hence 4th obesrvation is Median i.e 58

when we multiply the last three numbers by 5 still 4th obesrvation that is median remains same hence no effect