The data set is as follows: Ford, Ford, Chevy, Toyota, Ford, ...

[Yi-Chen]

The data set is as follows: Ford, Ford, Chevy, Toyota, Ford, Ford, Chevy, Dodge, Dodge, Dodge, Ford, Subaru, Chevy, Toyota, Chevy. What measures of central tendency and dispersion will be used with this set?
 
  a. Difference scores
  b. Range
  c. Median
  d. Mode

Question 2

Twenty student nurses take the NCLEX examination. If the average of the twenty scores is known, how many degrees of freedom are there in the sample?
 
  a. 18
  b. 19
  c. 20
  d. 21

[annierak]

Answer to Question 1

ANS: D
The data are not inherently numerical in nature and represent only a nominal level of measurement. None of the listed measures of variability are suitable for nominal-level data. The mode is the only measure of central tendency appropriate for nominal data. The mode is the numerical value or score that occurs with the greatest frequency in a data set.

Answer to Question 2

ANS: B
The concept of degrees of freedom was used originally in reference to computing a confidence interval, but it applies to any statistical computation. Degrees of freedom are the number of independent pieces of information that are free to vary in order to estimate another piece of information. If, for instance, the mean and the total n are known, if all of the values except one are known, the last one can be calculated. However, if all except two are known, one has the freedom to vary, and the other one's value is then set. In calculations, the degrees of freedom (df) are n  1. This means that there are n  1 independent observations in the sample of n data points that are free to vary (to be any value).

[Yi-Chen]

Wow, this really help

[ryansturges]

Excellent