doubt in mock test question 8

[sareena sanil]

which numerical summaries will not change if 7 is increased

the answer is range and std deviation 

but median and mode too doesnt change right?

[Rahul]

Set 1 : 12, 15, 18, 18, 27, 32

If we add 7 to each of these values, our set 2 will be 19, 22, 25, 25, 34, 39

Range of set 1 = 32 - 12 = 20

Range of set 2 = 39 - 19 = 20

Mode in set 1 = 18

Mode in set 2 = 25

Median in set 1 = 18

Median in set 2 = 25

Adding a constant to the observation doesn't change variance and standard deviation. So, range and standard deviation don't change. But, as you can see above, Mode and Median do.

[sareena sanil]

median in both set 1 and 2 with be 3rd or 4th observation right so it doesnt change 

[sareena sanil]

so we see the value of median and not the position?

[Statistics 1 Support 1]

Yes, We see the value of the median. The position is always the middle position.

Thanks,

Nitin Jha

Course support team