Exam 1 Part 2

Question 1

Has all the characteristics of interval scale, and ratios of values are meaningful (i.e., there is an absolute zero)

Answer 1

Ratio

Question 2

The variable of interest is called the ________ (or response, or outcome) variable, and the other is called _______ (or explanatory, or predictor).

Answer 2

Dependent, independent

Question 3

Summarize a sample of data using graphs and numerical measures such as means or percentages

Answer 3

Descriptive statistics

Question 4

We use the sample to reflect back on the population the sample represents

Answer 4

Inferential statistics

Question 5

Data are collected separately for both groups.

Answer 5

Independent samples

Question 6

Individuals are measured twice (e.g. before and after treatment), or individuals are matched in pairs (e.g. identical twins

Answer 6

Dependent samples

Question 7

Proportion of times an event will occur in the long run. Gives us the chance, or likelihood of that event occurring.

Answer 7

Probability

Question 8

What type of distribution is associated with degrees of freedom?

Answer 8

T-distribution

Question 9

The more df, the closer to _____

Answer 9

Normal

Question 10

The less df, the thicker the ____

Answer 10

Tails

Question 11

What are the 2 measurements of center?

Answer 11

Mean, median

Question 12

What are the 3 measurements of variation?

Answer 12

Range, standard deviation, Interquartile range (Q3 - Q1)

Question 13

What 3 criteria do we judge normality on (by lookin at a histogram)?

Answer 13

Modality (unimodal, bimodal), symmetry (symmetric, skewed), bell-shape

Question 14

What are the possible methods of analysis if both variables are categorical?

Answer 14

Compare percentages, contingency table, chi-square

Question 15

What are the possible methods of analysis if the variables are categorical and numeric?

Answer 15

Compare means, box plots, t-tests

Question 16

What are the possible methods of analysis if the variables are both numeric?

Answer 16

Scatterplot, coefficient correlation, regression analysis

Question 17

It is helpful to always use the independent variable for the ____, and the dependent variable for the ______

Answer 17

Rows, columns

Question 18

What 4 factors do we look at in a scatterplot?

Answer 18

Overall pattern (linear vs curved), strength (strong or weak), outliers, direction

Question 19

T/F: Correlation is sensitive to outliers

Answer 19

True

Question 20

T/F: IQR is sensitive to outliers

Answer 20

False; not