What kind of average would we use to represent the central tendency of the
incomes of everyone in this class most fairly?
Which of the following techniques is common among advertisers reporting the
results of clinical tests?
Using a ver
5 / 5 points
A normal distribution has a mean of = 100 with = 20. If one score is randomly
selected from this distribution, what is the probability that the score will have a
value between X = 80 and X = 100?
10. Interpreting percentiles A3 A3 E
A growth chart is a plot of the percentiles of growth measurements, such as weight and height, for a population of infants
or children. It is used by pediatricians to assess a childs growth over time.
The Centers for D
Practice #9 One-Way ANOVA pg. 1
1. A human-factors psychologist studied three computer keyboard designs.
Three samples of individuals were given material to type on a particular
keyboard, and the number of errors committed by each participant was
Chapter 12: Introduction
to Analysis of Variance
The Logic and the Process
of Analysis of Variance
The purpose of ANOVA is much the same as the
Goal is to determine whether the mean
differences that are obtained for sample data are
A hypothesis test is a statistical method that uses
to evaluate a hypothesis about a population.
The general goal of a hypothesis test is to rule out
(sampling error) as a plausible explanation
In general terms, central tendency is a statistical measure that
determines a single value that accurately describes the center
of the distribution and represents the entire distribution of
The goal of central t
Research begins with a question about a population
But we use samples and do inferential statistics
Inferential statistics are built on concept of probability
What is Probability?
Probability is a method for measuring and quantifying the
Samples and Populations
provide an incomplete picture of the
There are aspects of the population that may not
be included within a sample.
The sampling error is the error between a
Independent Samples t-tests
Allows researchers to evaluate the mean difference
between two populations using data from two separate
The identifying characteristic of the independentmeasures or between-subjects design
PSYC 2090: Intro to Statistics Spring 2017
Name: Yoruba Jones_
Recitation: Monday / Wednesday (circle one)
Repeated Measures (paired samples) t-test
You are researching the effects of alcohol on a motor speed/reaction time. For your experiment, you
Provides a quantitative measure of the
differences between scores and describes the
degree to which the scores are spread out or
URL for Xmax LRL
Method of Analysis:
In order to analyze the data set, several multiple linear regression t-tests were performed.
The marital attitude was used as the dependent variable and a subset of the demographic data
were used as the set of predictor variables. The
a. Percentage of Men: 52%
b. Mode: Men (Frequency 13)
c. Frequency: 11 for Divorced
Did not graduate from high
High School Graduate
b. Mean GPA= 28.27
2. For follow up, I would conduct an interaction comparison, like the tetrad contrast. Tetrads
evaluate the differences in population means between two levels of one factor are equa
Some Key Ingredients for Inferential Statistics: Z Scores, the Normal Curve, Sample versus Population, and
After studying this chapter, you should:
Be able to convert raw scores to Z scores.
Be able to convert Z