Describe the purposes of descriptive versus inferential statistics. - correct answer ✔✔-Descriptive
statistics describe and summarize data sets, while inferential statistics is used to test hypotheses
Describe and give an example of nominal and numerical data. - correct answer ✔✔-Nominal data is a
grouping variable or a difference of a kind. An example is gender or political affiliation
-Numerical data is a measurement or score or a difference of degree. An example is temperature.
List and describe three statistics used to describe nominal data. - correct answer ✔✔1. frequencies-
count, measured by a frequency bar chart
2. proportions- sample/population
3. percentages- proportionx100
In addition to frequencies, describe the two classes of statistics used to assess numerical data. List and
define the three examples from each class. - correct answer ✔✔-Central Tendency- the center or middle
of the distribution. Three examples of central tendency: mean (average), median (center/50th
percentile), mode (most occurring score)
-Variability- how spread out the data set is. Three examples of variability: range (highest score-lowest
score), variance (SD^2), and standard deviation (average deviation from the mean)
Describe how the standard deviation is similar to the mean as the "average deviation from the mean."
Include, with formulas, the ideas of a score, totaling of scores and averaging of scores. Be sure to
include, at each step, the formula for the deviation score, sum of squares and conclude with the full
formula for the standard deviation. - correct answer ✔✔mean:
x=score
Ex=total score
x(with - on top)=Ex/N=average scores
the three ideas of the mean are used in the standard deviation: