PSY 270 Statistics for Behavioral and Social Sciences
Chapter 3 Homework Z- Scores
Answer the following question using Chapter 3 and the Normal Curve Table in the Aron Text.
Some of the following questions you will need to utilize the formulas for turning
Amygdala Means of Amygdala Difference Scores Squared Deviations
explanation: what these answers mean is that on average the ac
PSY 270 Independent and Dependent T-tests- SPSS
There are basically two kinds of t-tests. The between-groups
(or independent means) t-test is a statistical test designed to
examine whether means from two different samples are
Hypothesis Testing Homework
Name:Morgan Wyatt _
Directions: The logic of hypothesis testing is the basis for all of the statistics well
look at for the rest of this class. Below are a number of scenarios that ask you to
identify the populations in
PSY 270 Ch. 6 HW.
1. Define alpha and beta
Alpha- the probability of rejecting the null hypothesis when the null hypothesis is true
Beta- the probability of failing to reject the hypothesis tested when that hypothesis is
false and a specific alternative h
PSY 270 Chapter 2 Homework
Name: Morgan Wyatt
1. Describe and explain the location of the mean, median and mode for the normal curve.
A normal curve is also referred to as a bell-shaped curve. The properties of a normal
curve are that being symmetrical a
PSY 270 Introduction Assignment Ch.1 Lab1
Name: Morgan Wyatt
List each of these variables under the appropriate label.
Stress level, class rank, religion, age, position finished in a race, birth order
position, Depression Level, number of Par
December 31, 2015
Total Current Assets
Net Fixed Assets
Liabilities & Owners
The Fair Trade Alternative
A Social Justice Issue in Less
Why do producers need Fair Trade?
The Case of Coffee
Over 50% grown by small scale farmers
Lack of direct access to the market
(dependency on middlemen)
Brazil in the Global
Review of Core-Periphery
Is Brazil a core or periphery
What characteristics should we
expect Brazil to have?
Brazil is the FIFTH largest country
in the world (area, population).
Which 4 countries are lar
Calculating the 95% and 99% Confidence Intervals
Let's use the 95% and 99% confidence interval examples in the course notes:
The formula is as follows:
Mean of the sample + (t or z critical value)(sample standard deviation / square root of n)
When to perform a z test vs. a t test
=> Under what circumstances do we use a t test? A z test? Please see page 6 of the course
notes: When the population standard deviation is unknown, it has to be estimated by using the
sample standard deviation(s). So
One-Tailed vs. Two-Tailed Tests
Remember that, in looking at the differences between the two groups, if the researcher is
trying to determine if there is an improvement or an increase in the dependent variable being
measured (or a deterioration or a decre
Finding the Critical Value
We only divide alpha by 2 when we are using the table to look up the critical value for a twotailed z test - but not for a one-tailed z test. For example, the critical z value for a two-tailed z
test with an alpha level of .05 i
Should the Critical z (or t) Value be Positive or Negative?
Is the critical z (or t) value + or - ?
The critical value can either be + or -, depending on the direction of the hypothesis . . . for
example, a two-tailed test that only hypothesizes a differe
Standard Deviation: How to Determine if You Have the Population or Sample Standard Deviation
Reading each problem very carefully will help you determine if the population standard
deviation or the sample standard deviation is being given. Sometimes the pr
THE NULL (H0) IS ACTUALLY TRUE
NULL (H0) IS ACTUALLY FALSE
Type 1 error
P = 1 - = Power
Fail to Reject H0
Type 2 error
1. A woman is found guilty but she is actually innocent. This is an
Type 1 and Type 2 Errors
The null hypothesis states that there is no difference.
A Type 1 error is possible when a researcher has rejected the null hypothesis - and determined
that there actually IS a difference - when the null hypothesis is actually true
The null hypothesis - and its opposite, the alternative hypothesis - are the conclusions that we state
after performing a z-test or a t-test and determining whether or not a difference between groups exists.
The hypotheses are our stated conclu
DOES THE DESCRIPTION OF THE EXPERIMENT.
hypothesize that there will be an increase or decrease? Or simply a difference?
If a difference:
- the test is two-tailed
- the symbol is = to the population mean for the null hypothesis
- the symbol is to the popul
Calculating the Standard Error and Sampling Distribution of the Mean
Central Limit Theorem- Given a population with a mean () and variance (2), the sampling
distribution of the mean will have a mean equal to and a variance equal to 2 / N (which is the
Confidence Intervals and the NEW Critical Value
For confidence intervals, we need to find a new critical value. For example, if you are asked to
find the new critical value for the 99% confidence interval, you would use The Normal
Distribution (z) table i
Psychology 1110 Midterm Exam - Dr. Joan Wigal
Elementary Statistical Reasoning - Online
You are allowed to have your textbooks, assignments, Instruction Materials, and any notes (and
tables) with you, as well as a calculator. However, you are not allowed
Solution to Midterm Examination
Note: There are four problems on this Exam worth a total of 100 points.
1. [50 points] Consider a two-way cross-classified ANOVA model
yij i j ij , i 1, 2; j 1, 2,3.
The parameters , i and j are
Note: There are three problems on this Exam.
1. [20 points] Let Y31 be a random vector such that E (Y ) M cfw_(a, a b,2b) | a, b .
a) [5 points] Show that M is a vector space.
Note that with (a, b)
In-class portion of the Final Exam consists of four problems, for a total of 40 points.
Individual scores for each problem are given on the left margin.
If needed, you can refer to
(Take Home Portion)
a. This take home portion of the Final Examination consists of five problems, for a total of
160 points (40% of the Overall Course Score). Individual scores for each problem are