Module 6, Standard Norm. Distribution

Question 1

What do z-scores do?

Answer 1

Based on raw scores and standard deviations and allows comparisons to be made across distributions
It gives the distance in standard deviations from a raw score to the mean of the distribution

Question 2

What is a critical value?

Answer 2

Critical Values: refer to values of z that cut off/act as boundaries of the distribution

Question 3

Features of a normal distribution

Answer 3

Bell curve
Unimodal
Symmetrical
Mean of 0
SD of 1
Personality traits and IQ distribute normally
Mean=median=mode
Areas under the curve are known; probabilities; Z-table
Mean divides the distribution into two equal halves: so does the median
Probability of .5 of selecting a value either above or below the mean
Follows Empirical rule: 68% within 1 SD, 95% within 2 SD, 99.5 within 3 SD,

Question 4

Sampling Distribution of the Mean

Answer 4

Complete set of means derived from random samples of a single sample size from a population
Systematically related to the population of raw values from which samples are drawn

Question 5

Central Limit Theorum

Answer 5

Provides characteristics of sampling distribution of the mean
Easier to use than obtaining all possible samples
Shape approaches a normal distribution with a greater sample size

Question 6

Standard Error:

Answer 6

standard deviation of the sampling distribution of the mean