Central Tendency 1
Central Tendency
As discussed previously distributions are described in terms of their shape, central tendency, and
variability. Today we will discuss central tendency.
A measure of central tendency is a single score that represents the
Variability 1
Variability
Previously we discussed the shape and central tendency of a distribution. Today, we will discuss a
distributions variability.
Variability is a measure of the extent to which scores are spread-out or clustered-together.
The follow
Frequency Distributions
1
Frequency Distributions
Purpose: To organize the presentation of data.
As an example, have each student indicate the number of siblings. Record haphazardly on the board their
responses. Ask them to summarize the results.
I. Frequ
Z-Scores 1
Z-Scores
As we have discussed during the previous lectures, a distribution is described in terms of its shape, central
tendency, and variability. Often, we are interested in describing not just a single distribution, but
describing and comparin
Introduction to Statistics
I. Statistics, Science, & Observations
what is statistics?
Statistics is a set of mathematical procedures used to organize, summarize, and interpret
information.
Psychologists use statistics for two general reasons:
- organize a
Practice Exam I
Follow the directions below carefully. Show all work! Remember to round to 4-decimal places.
1. Write out the equations for the following statistics.
a) X =
b) S2X =
c) rxy =
d) ZXi =
e) SX|Y =
f) SY|X =
2. Calculate the correlation betwee
PSY 3234 (Spring 2016)
Midterm Exam 3 (Practice)
1. Evolutionary theorists were interested in whether people spontaneously follow a 24-hour cycle of
sleeping and waking even if they are not exposed to the usual pattern of sunlight. To test this
notion, ei