L1: describing data

Question 1

variable types

Answer 1

categorical, continuous

Question 2

assumptions issues

Answer 2

misreporting, missing data, sample selection bias, estimation bias, integrity

Question 3

sample variance

Answer 3

s^2

Question 4

population variance

Answer 4

sigma ^2

Question 5

variance

Answer 5

avg of all squared deviations from mean

Question 6

larger variance means

Answer 6

greater dispersion of observations around mean (wider on graph)

Question 7

standard deviation

Answer 7

(s): square root of variance

Question 8

empirical (95%) rule

Answer 8

if data distribution symmetrical & bell shaped, approx 95% of data should be 2s.d. from mean. mean = median