PRACTICE QUESTIONS: SKEWNESS AND KURTOSIS
N Minimum Maximum Mean Std. Deviation Skewness Kurtosis
Statistic Statistic Statistic Statistic Statistic Statistic Std. Error Statistic Std. Error
How many total dollars do 400 $5.00 $450.00 $150.0525 $92.70629 .564 .122 .223 .243
you spend per month in
restaurants (for your meals
How likely would it be for 400 1 5 3.00 1.237 .155 .122 -.747 .243
you to patronize this
restaurant (new upscale
What would you expect an 340 $6.00 $60.00 $18.8353 $9.82784 1.388 .132 1.890 .264
average evening meal
entree item alone to be
Which section of the local 379 1 5 3.16 1.329 -.065 .125 -1.064 .250
newspaper would you say
you read most frequently?
What is your highest level of 400 1 8 5.77 1.413 -1.848 .122 3.320 .243
Which of the following 400 1 7 4.18 1.749 .200 .122 -.784 .243
categories best describes
your before tax household
Valid N (listwise) 321
1. What is the level of skewness for the variable, ‘Which section of the local newspaper would you say you read most
2. Is the level of skewness of any concern to the researcher? (no, not above + or – 2)
3. If the level of skewness for this variable in question one was, hypothetically, -2.44, would this be any concern to the
researcher (no because the variable is nominal so we don’t need to worry about it)
4. Because the level of skewness is negative, which way, compared to the normal curve, is the variable skewed (since its
negative, it is skewed to the left)
5. Which of the variables above have a level of skewness that requires more investigation (none since none are over + or
6. Which variable(s) have a level of kurtosis that requires more investigation? (‘highest level of education’)
7. What kind of variable is the one found in question 6, nominal or not nominal (for the purposes of the exam, assume
this variable is nominal)
8. What level is the kurtosis of the variable you identified in question 6? (3.320)
9. What kind of shape does the variable have in question 6: (pointier, compared to normal curve since it is positive)
10. If the kurtosis was -3.320, what kind of shape would that have (flatter than normal curve)
11. If we have high skewness or kurtosis and the variable is not-nominal, what do we use (non-parametric statistics)
12. Do either skewness or kurtosis have any significance values attached to them (NO: there are no significance or SIG
data given by SPSS for skewness or kurtosis!)
1 PRACTICE QUESTIONS: CORRELATIONS
IMPORTANT CLARIFICATION: If you are reading horizontally, (left to right) just count up ALL of the
significant ones all the way across, no matter what side of the red line they are on!!!
Many people make the mistake of reading both horizontally and vertically.
The red line is to prevent you double counting when you try to read both vertically and horizontally.
Note the top corner is identical to the bottom corner: .867, .000, 400.
The closer the correlation is to plus or minus one, the bigger (more important) it is.
The smaller the SIG, the more important it is.
Recoded How likely
How many total Would you income to would it be for
dollars do you describe Prefer Formal $1,000s using you to patronize
spend per month yourself as one Waitstaff What is your midpoints of this restaurant
in restaurants (for who listens to Wearing highest level of questionnaire (new upscale
your meals only)? the radio? Tuxedos education? Year Born ranges restaurant)?
How many total dollars do Pearson Correlation 1 -.106 .820 .602 -.431 .859 .867
you spend per month in Sig. (2-tailed) .034 .000 .000 .000 .000 .000
restaurants (for your meals