Chapter 5: Normal Distribution Standard Scores Flashcards Preview

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Flashcards in Chapter 5: Normal Distribution Standard Scores Deck (16):
1

When data is graphed it tends to naturally take what shape? List characteristics? (2)

- normal distribution -most points fall in centre, fewer towards extremes

2

What is an example of the naturally occurring standard distribution?

- Galton Board

3

What are the four characteristics of Normal Distribution?

1. symmetrical and bell-shaped 2. mean, median mode 3. asymptotic= extends forever without touching axis 4. area under the curve equals one

4

What are the two parameters of Normal Distribution?

1. mean 2. standard deviation

5

What are the normal distribution probabilities for 1, 2 and 3 standard deviations?

+/- 1= 68% +/- 2= 95% +/- 3= 99% anything after that is ~100%

6

What is a Z score?? (2)

1. A score that indicates how many standard deviations a raw score deviates from the mean 2. Comparisons relative to other participants

7

How do you interpret a Z score? (2)

1. Sign indicates above or below the mean ( left or right) 2. Magnitude indicates typical or atypical score!

8

What is an Atypical score and a typical score?

1. Atypical- outlier...not close to the mean... 2. Typical- closer to the mean...zero

9

What is the standard scores (z-scores) equation for populations and samples?

X=raw score to be standardized 

X bar= mean of population 

o= standard deviation of population 

*** difference between z score pop and z score sample is that the z score sample has a S!... 

10

Z scores are generally what? 

- unit free.....allowing one to compare distributions that have different units...

11

Standard scores ( z scores) characteristics? 

(3)

1. How many SD's a raw score varies from the mean 

2. Directionality (+/-) = above or below mean 

3. Magnitude = close or far from mean... 

12

With every Z score question you should draw what??

-standard distribution curve !  to help with solving the question..

13

You can rearrange the z score formula to also solve for? 

- the raw score..... 

14

Z scores can determine the area associated with z scores and therefore the __________ are also possible to find. 

The percentages of scores __ or ____ a given raw score. 

- percentile rank 

-at, below 

15

When looking at a Zscore chart......What does Comumn A, B and C represent? 

- A: z score ( always positive ) 

-B: area between mean and z score 

-C: area beyond the z score 

16