In estimating the parameters of a population of students ...

[dakota nelson]

In estimating the parameters of a population of students categorized by year in school, which of the following estimators is the most nonbiased?
 
  a. Mean
  b. Median
  c. Standard deviation
  d. Variance

Question 2

The median is represented by which score in the following frequency distribution? X f 12 3 11 0 10 1 9 1 8 1 7 1
 
  a. 12
  b. 10
  c. 9
  d. 7

[jaymee143]

Answer to Question 1

ANS: B
Categories of year in school (freshman, sophomore, junior, and senior) indicate ordinal data. The median is the most appropriate measure of central tendency for ordinal data.
Year in school is ordinal data; a mean cannot be calculated on ordinal data. Categories of year in school (freshman, sophomore, junior, and senior) indicate ordinal data. The median is the most appropriate measure of central tendency for ordinal data.
Standard deviation requires at least interval level data for calculation. Categories of year in school (freshman, sophomore, junior, and senior) indicate ordinal data. The median is the most appropriate measure of central tendency for ordinal data.
Variance requires at least interval level data for calculation. Categories of year in school (freshman, sophomore, junior, and senior) indicate ordinal data. The median is the most appropriate measure of central tendency for ordinal data.

Answer to Question 2

ANS: B
The median is the score at the exact center of the frequency distribution (the 50th percentile). The median is obtained by first rank ordering the scores, then identifying the score at the exact center. In this example, rank ordering of the scores would be: 7, 8, 9, 10, 12, 12, 12. 10 is the center score.
Twelve is the mode. The median is the score at the exact center of the frequency distribution (the 50th percentile). The median is obtained by first rank ordering the scores, then identifying the score at the exact center.
The median is the score at the exact center of the frequency distribution (the 50th percentile). The median is obtained by first rank ordering the scores, then identifying the score at the exact center.
The median is the score at the exact center of the frequency distribution (the 50th percentile). The median is obtained by first rank ordering the scores, then identifying the score at the exact center.

[dakota nelson]

Gracias!

[patma1981]

TYSM