×
Get Full Access to UA - Psych 2110 - Study Guide - Midterm
Join StudySoup
Get Full Access to UA - Psych 2110 - Study Guide - Midterm

×

UA / Psychology / PY 211 / What are the two conditions that determine a probability distribution?

# What are the two conditions that determine a probability distribution? Description

##### Description: Study guide for Exam 2. Happy Studying!
3 Pages 144 Views 1 Unlocks
Reviews

From 211 Elementary Statistical Methods (Psychology) ; Professor Souza

## What are the two conditions that determine a probability distribution?

Chapter 3 & 4 Test Review

Ideas Stressed in Chapter Three:

­ Chapter Three homework is very important for Exam 2

­ Practice reading graphs (examples are lower)

­ Familiarize yourself with the terms and formats used for questions

Probability Distributions = ​A variable can take at least two different values (each possible value has a probability that it occurs; lists all possible outcomes and probabilities)

Discrete Variables ​= specific values and that cannot have values between these specific values

Z­scores

­ Transformation of a number into a correlating number from ­3 to 3 in order to find probability

## Which of the following is an example of discrete variable?

X−M

Z =  or Z =  SD

X−M σ

­ X symbolizing the score, M symbolizing the mean, and SD (or σ) symbolizing the standard deviation

167−170

­ For example, a girl has a height of 167. Z =  ; thus z = ­.3 for probability. 10 ­ ­.3 relates to a number on the ­3 to 3 scale

From 211 Elementary Statistical Methods (Psychology) ; Professor Souza

Ideas Stressed/Re­stressed in Chapter Four:

­ Statistics =​ random variables

­ Inferential Statistics =​ procedures for drawing conclusion based on the scores collected in a research study but going beyond them; creates an educated guess for studies where it is impossible to question the entire population

## What are the steps in the hypothesis testing procedure?

Don't forget about the age old question of How much charge is enclosed by the gaussian surface?

­ Memorize the Standard Distribution Variance Formula (Depicted below) Hypothesis Test = ​A sample statistic is the best option for making an educated guess

Summary of the five steps of the​ hypothesis­testing procedure:

1. Restate the question as a research hypothesis and a null hypothesis about the populations.

2. Determine the characteristics of the comparison distribution.

3. Determine the cutoff sample score on the comparison distribution at which the null hypothesis should be rejected.

4. Determine the sample's score on the comparison distribution.

5. Decide whether to reject the null hypothesis.

Showing the null hypothesis to be true would mean showing that there is absolutely no difference between the populations. It is always possible that there is a difference between the populations but that the difference is much smaller than the particular study was able to detect. Therefore, when a result is not extreme enough to reject the null hypothesis, the results are said to be inconclusive. Don't forget about the age old question of What is the spanish term for to put?

Central Limit Theorem

Formula:  √nσ If you want to learn more check out What is the meaning of census?

Standard Error =​ How much the sample mean would vary if we took several samples at the same size from the same sample

Application

1. Usually just grab one sample

2. Take the z­score for this sample (distance from the mean)

Formula: z =

x̄− M √nσ

x̄− M

or z =   SD

From 211 Elementary Statistical Methods (Psychology) ; Professor Souza

Hypothesis Testing Cont.

­ Objective = ​check whether a set of data agrees with a certain prediction ­ Prediction = hypothesis → statement about a population, a guess that a parameter takes a particular numerical value or falls within a particular interval, systematic way to test claims or ideas about a population

­ A significance test uses data to summarize the evidence about a hypothesis (comparing sample statistics or point estimates of parameters) to the values predicted by the hypothesis

Four Basic Steps

­ State the hypothesis We also discuss several other topics like Why are peppers with different colors?
Don't forget about the age old question of What do sociologists refer to as the ability to see the relationship between individual experiences and the larger society?
Don't forget about the age old question of What is the meaning of social policies?

­ Set a criteria for decision (basically choose a α­level) *Has to be done before observations

­ Compute the test statistic (collect data)

­ Compare and make a decision

Happy Studying!

Page Expired
It looks like your free minutes have expired! Lucky for you we have all the content you need, just sign up here
References: