Chalter 3+4 Flashcards

1
Q

Central tendency

A

The most typical, central, or common score of a variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

3 measures of central tendency

A

Mean
Median
Mode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Mode

A

Most common score

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Median

A

Score of the middle case

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Mean

A

Average score

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Dispersion

A

Variety, diversity, or amount of variation between scores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Measures of dispersion

A

Index of qualitative variation
Range, interquartile range
Variance, standard deviation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mind the median

10,10,8,7,5,4,2

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Find the range
10,10,8,7,5,4,2

A

10-2=8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A

Mean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Calculate x̄

10,20,30,40,50

A

150 ➗5= 30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What scores does the mean use

A

All scores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a skewed distribution

A

Pulling the mean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Positive skewed distribution

A

Pulls the mean to the right

Mean> median

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Negative skewed distribution

A

Pulls the mean to the left

Mean< median

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Unskewed distribution

A

In the middle

Mean= median

Doesn’t happen in fact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Standard deviation

A

Average distance of each score to the mean

18
Q

Variance

A

Square of standard deviation

19
Q

3 characteristics of standard deviation

A

Use all score in a distribution
Lowest possible value is 0
Increase in value as distribution

20
Q

How to find standard deviation (5)

A
  1. Subtract mean from each score
  2. Square each deviation
  3. Add squared deviations
  4. Divide the sum of squared deviations by the # of scores
  5. Find the square root of the result
21
Q

Characteristics of the normal curve

A

-bell shape
-symmetrical/ unimodal
-theoretical

22
Q

Units for z scores

A

Units of standard deviation

23
Q

What level of measurement is used for z-scores

A

Interval ratio

24
Q

2 characteristics of under the normal curve

A

Above or below a given score
Between two given scores

25
Q

Where to look to find the area above and below z positive or negative

A
26
Q

Example of a discrete variable

A

Rolling a die

27
Q

Example of a continuous variable

A

Body weight

28
Q

What is a normal curve

A

A bell shaped theoretical distribution of scores

29
Q

What is probability

A

Ratio of number of success to number of possible events

30
Q

Percentage between -1 & +1 SD

A

68.26

31
Q

Percentage between -2 & +2 SD

A

95.44%

32
Q

Percentage between -3 & +3 SD

A

99.72%

33
Q

What is a Z-score

A

The way scores are expressed after they have been standardized to the theoretical normal curve

34
Q

Index of qualitative variation

A

Amount of variation observed in a distribution of normal or ordinal-level variables scores to the maximum variation that could exist

35
Q

outliers

A

Extreme high or low scores in a distribution

36
Q

interquartile range

A

distance from the 3rd quartile to the 1st quartile

37
Q

5 number summary

A

lowest score
highest score
median
1st quartile
3rd quartile

38
Q

deviations

A

distance between the scores and mean

39
Q

mean deviation

A

average of absolute deviations of the scores around the mean

40
Q

coefficient of variation

A

ratio of SD to the mean