Unit 3

Question 1

Interpreting Correlation Coefficient

Answer 1

a statistical index of the relationship between two things (from -1 to +1)

Question 2

Association in a Two Way Table

Question 3

Bivariate Data

Answer 3

Consists of two variables, an explanatory and a response variable.

Question 4

Two Way Table

Answer 4

A table containing counts for two categorical variables. It has r rows and c columns.

Question 5

Scatterplot

Answer 5

a graphed cluster of dots, each of which represents the values of two variables

Question 6

Different Types of Association in a Scatterplot

Answer 6

Direction (Positive/Negative), Form (Linear), Strength (Strong, Moderate, Weak)

Question 7

Correlation Co

Question 8

Response Variable

Answer 8

A variable that measures an outcome

Question 9

Explanatory Variable

Answer 9

a variable that we think explains or causes changes in the response variable

Question 10

Interpret Least Squares Line (Line of Best Fit)

Answer 10

a line drawn in a scatter plot to fit most of the dots and shows the relationship between the two sets of data

Question 11

Interpret a Residual Plot

Answer 11

a scatterplot of the residuals (results) against the explanatory variable (what is assumed)

Question 12

Intercepts of a Line

Answer 12

The intercepts of a line are the points where the line crosses, the horizontal and vertical axes

Question 13

Slope of a Line

Answer 13

y2-y1/x2-x1 , interprets the direction

Question 14

Coefficient of Determination

Answer 14

a measure of the amount of variation in the dependent variable explained by the regression equation

Question 15

Equation of a Fitted Line

Question 16

Interpolation

Answer 16

Allows estimation of a datapoint within a dataset

Question 17

Extrapolation

Answer 17

Allows estimation of a datapoint out of a dataset

Question 18

Observed Association vs Causal Relationship

Answer 18

Correlation does not indicate causation

Question 19

Non Causal Explanations for an Association

Answer 19

1. Coincidence
2. Confounding due to a common response from a separate variable

Question 20

Time Series Plot

Answer 20

Obtained by plotting the time in which a variable is measured on the horizontal axis and the corresponding value of the variable on the vertical axis. Line segments are then drawn connecting the points.

Question 21

Time Series Plot Trends

Answer 21

Trend (The increasing or decreasing value in the series) , Seasonality (The repeating short-term cycle in the series) and Irregular Fluctuations (Random drops and rises in data).

Question 22

Smooth Time Series Data

Answer 22

Data can be smoothed by using a simple moving average