A survey was taken of students in math classes to find out how many hours per day students spend on social media. The survey results for the first-, second-, and third-period classes are as follows:

First period: 2, 4, 3, 1, 0, 2, 1, 3, 1, 4, 9, 2, 4, 3, 0

Second period: 3, 2, 3, 1, 3, 4, 2, 4, 3, 1, 0, 2, 3, 1, 2

Third period: 4, 5, 3, 4, 2, 3, 4, 1, 8, 2, 3, 1, 0, 2, 1, 3

Question

A survey was taken of students in math classes to find out how many hours per day students spend on social media. The survey results for the first-, second-, and third-period classes are as follows:

First period: 2, 4, 3, 1, 0, 2, 1, 3, 1, 4, 9, 2, 4, 3, 0

Second period: 3, 2, 3, 1, 3, 4, 2, 4, 3, 1, 0, 2, 3, 1, 2

Third period: 4, 5, 3, 4, 2, 3, 4, 1, 8, 2, 3, 1, 0, 2, 1, 3

anonymous · Answer

Which is the best measure of center for second period and why?

 Mean, because there are no outliers that affect the center
 Median, because there is 1 outlier that affects the center
 Interquartile range, because there is 1 outlier that affects the center
 Standard deviation, because there are no outliers that affect the center

anonymous · Answer

@welshfella

kropot72 · Answer

Can you see any outliers in the data for the second period?

anonymous · Answer

wait

anonymous · Answer

Yes 0

anonymous · Answer

0 is an outliner in second period

kropot72 · Answer

I don't think that zero is an outlier. It is not far removed from the other values in the set.

anonymous · Answer

But its the least common and it has the least ammount from the data set not to mention its the furthest from all the numbers.

kropot72 · Answer

An example of an outlier is 9 in the first period.

anonymous · Answer

Outliner - A value that "lies outside" (is much smaller or larger than) most of the other values in a set of data.

anonymous · Answer

The outliner is 8 in 3rd period

kropot72 · Answer

There are accepted ways to decide whether or not a point should be regarded as an outlier.
A point is an outlier if:
1) It is more than two standard deviations away from the mean
or
2) It is more than 1.5 times the inter-quartile range away from the nearest quartile.

Do you want to use one of these methods to decide whether or not 0 is an outlier in the data for the second period?

anonymous · Answer

Sure why not

anonymous · Answer

There are no Outliners in Second Period.... are there?

kropot72 · Answer

I believe that there are no outliers in the data for the second period. If you accept that, the choice of answer is between A and D. Is the standard deviation a measure of the center?

anonymous · Answer

Its a measurment done from the mean

anonymous · Answer

that is what a stander mediation is

kropot72 · Answer

Standard deviation is a measure of spread. It is not a measure of the center. Can you now see what is the correct choice of answer?

anonymous · Answer

yes its A

anonymous · Answer

Thank you very much Kropot

kropot72 · Answer

You're welcome :)