Exam 3 Flashcards
What is an appropriate measure to summarize ordinal data
Median
When a line graph is employed to represent the number of subjects who received each possible score on a variable, this graph is called a frequency ____\
Polygon
What is the difference between descriptive and inferential statistics?
Descriptive statistics summarize data
Inferential statistics determine the probability that results are due to chance
If you were to graph the results of tatste test between two different types of beverages, the type of beverage w hod appear on the
Horizontal axis
What would be an appropriate measure of centeral tendency to summarize interval data
Mean median and mode
In a _____ a separate and distinct _____is drawn to represent the number of people who received a possible score
Bar graph
Bar
The standard deviation would be an appropriate measure of variability only if the variable is measured on a _____ scale
Interval
In a survey examining the number of third vs 6th grade students who buy their lunch at school, the most appropriate description of the results would be to
Compare group percentages
A researcher wants to graph the results of a study that examined of food consumption affected preference for a movie. In This example, the preference for the movie should appear ___\
On the vertical axis
Example of histograms or frequency polygons
“clustered column” (Excel) or line graphs
Sampling error
When you only have a sample and not the entire population. This can result in skewed values
Statistic vs parameter
Statistic- characteristic of a small part of the population, i.e. sample.
parameter-fixed measure which describes the target population.
The statistic is a variable and known number which depend on the sample of the population while the parameter is a fixed and unknown numerical value.
Descriptive statistics
uses the data to provide descriptions of the population, either through nu
Inferential statistics
makes inferences and predictions about a population based on a sample of data taken from the population in question.
3 characteristics that completely describe a distribution:
Shape, central tendency & variability
Normal distribution shape
Symmetrical. Bell curve
Histogram/frequency polygon chart shape
Skewedness. Can be positive to negative
Frequency distribution
Shows number of instances in which a variable takes each of its possible values.
Central Tendency
– It is the score that indicates where on the scale the distribution is located
– It indicates the value of the variable around which most of the scores are found.
– A measure of central tendency is usually (but not always) near the center of the distribution.
Population
μ, N
Sample
n
_
X(or M)
Mode
Score that shows the most
Can be used on all for scales of measurement measurement (nominal, ordinal, interval, ratio)
Only one that can be used for nominal dependent variables
What is the only central tendency that can be used for nominal dependent variables
Mode
What can be used on all four scales of measurement
Mode