Do students' scores on a TOEFL examination cluster about a single point or do the scores vary over a large spectrum? To answer this question, a researcher makes a data file of TOEFL scores and then gets descriptive statistics for the data. The data below represent a single variable. They are in columns only to save paper.

Data file: dsstudy1.sav
Variable: TOEFL

TOEFL
465     538
538     465
499     439
439     469
490     490
450     490
476     420
420     466
499     560
560     599
581     590
590     481
441     489
489     441
439     590
600     440
548     507
501     536
547     540
588     550
560     551
530     578
500     501
451     503
489     500
 

Answer the following questions:

1. Are the these data nominal, ordinal, or interval?
   
    
2. Provide three figures to indicate the central tendency of these data.
    
   
   
   
    
3. Provide two figures to indicate the dispersion of these data.
    
   
   
   
   
4. Do these data have any problems with kurtosis or skewness? If so, explain with data.
    
    
   
    
5. Approximately 68% of the scores will fall within one standard deviation of the mean.
   a.  State the 68% limits (upper and lower) of variation for the data.
   b.  What crucial assumption about the distribution of the data does this calculation require?