Chapter 2

Question 1

Frequency table

Answer 1

Shows the counts of each categorical variable

Question 2

Proportion

Answer 2

Number who agree/ total

Question 3

Two way table

Answer 3

A visual used to show the relationship between 2 categorical variables

Question 4

Dotplot

Answer 4

Dot placed over the axis for each case in the dataset. Good for small data sets

Question 5

Histogram

Answer 5

Groups quantitative data into bins. X axis is numeric

Question 6

Bar charts

Answer 6

Splits categorical data up into fixed groups. X axis is not numeric

Question 7

Symmetric distribution

Answer 7

If folded over s vertical line, the two sides of the plot match closely

Question 8

Skewed distribution

Answer 8

Data is piled up on one side of the graph

Question 9

Right skew

Answer 9

data piled to the left, tail extends right

Question 10

Left skew

Answer 10

data piled to the right, tail extends left

Question 11

Bell shaped distribution

Answer 11

Plot is symmetric and bell shaped

Question 12

Resistance

Answer 12

A stat is relatively unaffected by extreme values. Median is resistant, mean is not

Question 13

Outlier

Answer 13

Observed value is noticeably distant from other data points

Question 14

Standard deviation

Answer 14

Measures the spread of the data in a sample

Question 15

The larger the standard deviation…

Answer 15

The more data variability

Question 16

95% rule

Answer 16

If distribution is bell shaped, 95% of the data falls within two standard deviations of the mean

Question 17

Z score

Answer 17

Tells how many standard deviations a data value is from the mean and can determine how unusual it is

Question 18

How to find a z score

Answer 18

(Value - mean) / standard deviation

Question 19

Percentiles

Answer 19

The pth percentile is the value of a qualitative variable greater than p% of the data

Question 20

Five number summary

Answer 20

Minimum, maximum, median, Q1 and Q3. This set divides the datasets into fourths

Question 21

Interquartile range

Answer 21

Q3-Q1

Question 22

Range

Answer 22

Maximum - minimum

Question 23

Box plot

Answer 23

Graphical display of the 5 number summary for a single quantitative variable

Question 24

Side by side graph

Answer 24

Used when there’s 1 categorical and one quantitative variable. Includes a graph for the q variable for each group in the c variable

Question 25

Bubble plot

Answer 25

A scatter plot where the size of the point depends on another variable

Question 26

Time series plot

Answer 26

Plot that places time on the horizontal axis and a quantitative variable on the vertical. Helps visualize trends over time

Question 27

Spaghetti plots

Answer 27

Plot all available measurements and connect the points within each subject with a line

Question 28

Residuals

Answer 28

Difference between observed and predicted values of the response variables

Question 29

Residual calculation

Answer 29

Observed value - predicted

Question 30

Negative residuals are ___ the line Positive residuals are ___ the line

Answer 30

Below, above