Review MT1

Question 1

Cross-sectional data

Answer 1

Data collected at the same, or approximately the same, point in time

Question 2

Coefficient of variation

Answer 2

Compares two variables to see which is relatively more dispersed
compare variation between 2 data sets

Question 3

Standard deviation

Answer 3

Shows dispersion within a single variable

Question 4

Correlation coefficient

Answer 4

Compares two variables to see whether they move together (i.e. as one increases the other increases, or as one increases the other decreases)

Question 5

Cumulative relative frequency

Answer 5

Shown in an ogive, this shows how much of the data is at this point or before

Question 6

Stratified sampling

Answer 6

Split the country into districts, and within each, administer proficiency tests to auto mechanics working on Fords.

Question 7

Convenience sampling

Answer 7

Talk to 30 people going to the movies in Towson about whether they’d pay more to have a nicer theater nearby.

Question 8

Cluster sampling

Answer 8

Split the country into zip codes, and from them choose 50 in which to count all fast food restaurants.

Question 9

Systematic sampling

Answer 9

First choose one post office from the first 1000 listed alphabetically by city, and then every 1000th post office from there on.

Question 10

variance

Answer 10

[Σ(x - x-bar)2] / (n-1)

Question 11

standard deviation

Answer 11

SQRT ([Σ(x - x-bar)2] / (n-1) )

Question 12

z-score

Answer 12

(x -μ) /σ

data something people have no idea about

Question 13

correlation coefficient

Answer 13

rxy=sxy/(sxsy)

Question 14

covariance

Answer 14

[Σ(x - x-bar)(y - y-bar)]/(n-1)

Question 15

Observational studies

Answer 15

Statistical studies in which researchers do not control variables of interest

Question 16

Quantitative data uses

Answer 16

histogram
cross-tabulation
scatter plot
frequency distribution chart
dot plot
ogive

Question 17

Qualitative data uses

Answer 17

pie charts
relative frequencies
frequencies
cross-tab