Question

I need to find the mean and standard deviation for this data

SE-FamilySize
2
2
1
2
4
4
3
2
1
4
2
4
2
4
3
4
4
3
5
5
6
2
3
4
3
3
2
4
2
2

Answer 1

Here it is not specified whether the data given is of the whole population or of a sample

The Mean remains the same irrespective of the data is sample or population

Mean = Sum of all the values / Number of values

= 92 / 30

= 3.066667 rounded to 6 decimal places

If the data is of whole population, then

Standard Deviation = [ (X_i - )² ] / Number of values

= 43.86667 / 30

= 1.462222

= 1.202922 rounded to 6 decimal places

If the data is of sample, then

Standard Deviation = [ (X_i - )² ] / (Number of values - 1)

= 43.86667 / 29

= 1.512644

= 1.229896 rounded to 6 decimal places