Critical numbers 3- summary statistics II

Question 1

distribution

Answer 1

shape pof the data distribution

Question 2

central tendency

Answer 2

average or typical values

Question 3

dispersion

Answer 3

how spread out data are around these values

Question 4

range

Answer 4

min and max observed values

Question 5

Key things looking for when summarising numerical data:

Answer 5

distribution, central tendency, dispersion, range

Question 6

features of normal distribution

Answer 6

bell shaped curve, mean = median

Question 7

features of positive skew

Answer 7

skewed to right skew (tail on right hand side), mean is higher than median

Question 8

features of negative skew

Answer 8

skewed to left skew (tail on left hand side), mean is lower than median

Question 9

parametric vs non-parametric

Answer 9

parametric- make distributional assumptions
non-parametric- make no assumptions (distribution free)

Question 10

sd rule- 1, 2, 3 sd

Answer 10

68- 1 sd
95- 2 sd (anything higher than this viewed as abnormal)
99.7 - 3sd

Question 11

correlation

Answer 11

measure of linear association between 2 variables, between 1 and -1, 0 describes linear relationships (not just no correlation)