Chapter 1

Question 1

individual

Answer 1

objects described by a set of data`

Question 2

variable

Answer 2

any characteristic

Question 3

categorial variable

Answer 3

puts an individual into one of several groups

Question 4

quantitative variable

Answer 4

takes numerical values to find an average
some exceptions ie zip code

Question 5

distribution

Answer 5

shows what values a variable takes and how often it occurs

Question 6

frequency table

Answer 6

displays counts (frequencies) of individuals in a category

Question 7

relative frequency table

Answer 7

shows percentages (relative frequencies) of individuals in a category

Question 8

roundoff error

Answer 8

rounded percents only come close to 100%
only points out the effects of rounding off results

Question 9

marginal distribution

Answer 9

a distribution of values for one variable

Question 10

conditional distribution

Answer 10

separate distributions for each variable

Question 11

association

Answer 11

exists between two variables if knowing the value of one helps predict the other

Question 12

symmetric distribution

Answer 12

left and right are mirror images

Question 13

skewed left/right

Answer 13

a tail to the left/right side

Question 14

unimodal

Answer 14

single peak

Question 15

bimodal

multimodal

Answer 15

two peaks

three or more peaks

Question 16

stemplots

Answer 16

gives a quick peak into the shape of a distribution

Question 17

histogram

Answer 17

only for QUANTITATIVE data
% on the y axis, values on the x axis

Question 18

mean

Answer 18

average, how large data would be if data was split evenly
x bar – sample
mew – population
this is for symmetric data `

Question 19

median

Answer 19

midpoint of distribution
if the number of observations is odd, the median is the center observation
if the number of observations is even, the median is the average of the two center observations
this is for skewed data

Question 20

range

Answer 20

largest data value - the smallest view
should be ONE value

Question 21

mode

Answer 21

value that occurs most often

Question 22

interquartile range

Answer 22

Q1 – 25%; to the left of the median
Q2 – 50%; the median
Q3 – 75%; to the right of the median

Question 23

1.5 IQR Rule

Answer 23

allows for an observation to be called an outlier if it is outside Q1 - 1.5IQR and Q3 - 1.5IQR
boundaries

Question 24

five number summary

Answer 24

minimum, Q1, median, Q3, maximum

Question 25

standard deviation

Answer 25

measures the distance from the mean

Question 26

variance

Answer 26

standard deviation squared

Question 27

to describe (CSOCS)

Answer 27

Context
Shape – skewed/symmetric
Outliers
Center
Spread – range
Use comparative words