QUIZ #1, 302, Fall 99 WITH ANSWERS MARKED
*Please bubble in answers to the first five questions on the group scantron*
1. Social scientists use frequency tables, histograms, or frequency polygons to demonstrate
a. the conclusions they draw from the numbers they collect.
b. the reasoning behind experiments.
**d. how the numbers they collect are distributed.
2. In a histogram, the horizontal (across) dimension represents
**a. possible values the variable can take.
b. intensity of the variable.
c. mean score.
3. The median is greater than the mean in a distribution that is
b. positively skewed.
**d. negatively skewed.
4. A professor gives an exam in an introductory statistics class and after making a frequency distribution discovers that most students got a perfect score. This is an example of a
a. symmetrical distribution.
b. positively skewed distribution.
**c. ceiling effect.
d. both b and c.
5. If the variance of a set of scores is 9, what is the standard deviation of that set of scores?
*Write answers to next questions on this sheet. Please write neatly. Be sure to consult all group members before writing your answers.*
6. The variance of a group of scores is the average of the
__Squared deviations from the mean______________________.
7. If a raw score is 28 and M = 20, SD = 2, then the Z score is ___4___. Show how
you got your answer.
Z=(X-M)/SD (28-20)/2 = 8/2 = 4
or shown worked out graphically with the number line
8. What is a parameter?
A number (or index) that summarizes a feature of a POPULATION distribution
Give two examples of parameters that statisticians frequently use
Mean , Variance, Standard Deviation, Skew, Kurtosis