2- Frequency Distributions

Question 1

group frequency distributions

Answer 1

the “x” lists group of scores (class intervals), rather than individual values

Question 2

what are the 3 rules for group frequency distributions

Answer 2

1) should have about 10 class intervals
2) width of each interval should be super simple (2 ,5,10)
3) the bottom score in each class interval should be a multiple of the width (40-49) (10= width)

Question 3

what is a normal/ bell curve?

Answer 3

symmetrical

Question 4

what is a skewed curve?

Answer 4

when the scores tend to pile up on one end of the scale and tapper off gradually

Question 5

positively skewed: scores tend to pile up on ___, tapper off ____

Answer 5

scores tend to pile up on left, tapper off right

Question 6

negatively skewed: scores tend to pile up on _____, tapper off ____

Answer 6

negatively skewed: scores tend to pile up on right, tapper off left

Question 7

central tendency

Answer 7

a statistical measure to determine a single score that defines the centre of a distribution

Question 8

Mean for a population =

Answer 8

μ = ∑X / N

Question 9

Mean for a sample =

Answer 9

M = ∑X / n

Question 10

adding a new score, or removing, _________ the mean.

Answer 10

adding a new score, or removing, will change the mean.

Question 11

changing the value of any score __________ the mean.

Answer 11

changing the value of any score will change the mean.

Question 12

the mean will not be changed if….

Answer 12

the mean will not be changed if the new (or removed) score is exactly equal to the mean

Question 13

the median

Answer 13

locate the midpoint of a distribution, by placing them in order smallest-largest

Question 14

the mode

Answer 14

score or category that has the greatest frequency

Question 15

which method of central tendency do you use for: extreme scores or skewed distributions

Answer 15

Median

Question 16

which method of central tendency do you use for: undetermined values

Answer 16

Median

Question 17

which method of central tendency do you use for: Open ended distributions (3+)

Answer 17

Median

Question 18

which method of central tendency do you use for: Ordinal Data

Answer 18

Median

Question 19

which method of central tendency do you use for: Nominal Scale

Answer 19

Mode

Question 20

positively skewed goes _____, ______, and ________

Answer 20

mode, median, and mean

Question 21

negatively skewed goes _____, ______, and ________

Answer 21

mean, median, and mode

Question 22

What graph do you use for Intervals or Ratios?

Answer 22

Histogram

Question 23

What graph do you use for Nominal or Ordinal Scales

Answer 23

Bar Graph