Math 147 Chapter 2

Front 1

Descriptive Statistics

Back 1

The process of organizing, summarizing, and presenting the data collected

Front 2

Raw Data

Back 2

The data obtainedfrom either observational studies or designed experiments; this data must be organized into meaningful firm of table and graphs

Front 3

Frequency Distribution

Back 3

A table that shows classes or intervals of data with a count of the number of entries in each class; lists each category of data and the number of occurrences for each category of data

Front 4

Class Width Formula

Back 4

Is the range of data ÷ the number of classes

Front 5

Range of Data Formula

Back 5

Maximum number of data minus the minimum number of data

Front 6

Steps Finding Class Width

Back 6

1) determine the range of data

2) divide the range by the number of classes

3) round up to next convenient number

Front 7

Steps Find Frequency Distribution

Back 7

1) decide on number of classes

2) find class width

3) find class limit

Front 8

Finding Class Limits

Back 8

1) start with minimum data entry

2) add the class width to lower limits

Front 9

Bar Graph

Back 9

constructed by labeling each category of data on either the historical or vertical axis and the frequency or relative frequency of the category on the other axis

Front 10

Parto Chart

Back 10

A bar graph whose bars are drawn in decreasing order of frequency or relative frequency

Front 11

Pie Chart

Back 11

A circle divided into sectors. Each sector represents a category of data. The area of each sector is proportional to the frequency of the category

Front 12

Classes

Back 12

Categories of data; are the categories by which data are grouped

Front 13

Lower Class Limit

Back 13

The smallest value within the class

Front 14

Upper Class Limit

Back 14

The largest value within the class

Front 15

Class Width

Back 15

The difference between consecutive lower class limits

Front 16

Open Ended

Back 16

If the table's first class has no lower class limit or the last class does not have an upper class limit

Front 17

Finding Upper Class Limit

Back 17

By subtracting one less than the lower limit of the second class

Front 18

Frequency Distribution VS Relative Frequency Distribution

Back 18

FD: shows the number of observations that belong in each category

RFD: shows the proportion of observations that belong in each category

Front 19

Relative Frequency Formula

Back 19

Relative frequency = frequency ÷ sum of all frequencies

Front 20

Relative Frequency

Back 20

The proportion (or %) of observations within a category

Front 21

Relative Frequency Distribution

Back 21

Lists each category of data together with the relative frequency

Front 22

Histogram

Back 22

A bar graph that represents the frequency distribution which the horizontal scale is quantitative and measures data values and the vertical scale measures the frequencies (or relative frequencies) of the classes. Consecutive bars must touch!

Front 23

Stem and Leaf Plot

Back 23

Each number is separated into a stem and leaf; it's similar to a histogram and still contains original data values. Another way to represent quantitative data graphically

Front 24

Stem

Back 24

Formed by using the digits to the left of the right most digit

Front 25

Leaf

Back 25

Formed by using the right most digit

Front 26

Spilt Stems

Back 26

Rather than using one stem for the class of data, two stems can be used

Front 27

Dot Plot

Back 27

A graph drawn by placing each observation horizonally in increasing order and placing a dot above the observation each time it's observed

Front 28

Time-Series Plot

Back 28

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.

Front 29

Time Series Data

Back 29

The value of a variable measured at different points in time

Front 30

Bar Chart

Back 30

A graph for depicting qualitative data and which the bars must be separated

Front 31

Pie Chart

Back 31

A circle divided into sectors that represent different categories. The area of each sector is proportional to the frequency of each category.

Front 32

Shape of Distribution

Back 32

Typically classified symmetric, skewed left, or stewed right

Front 33

Symmetric Distribution

Back 33

Histograms are mirrored images

Front 34

Uniform Distribution

Back 34

Frequency of each value of the variable is evenly spread out across the value of the variables

Front 35

Bell-Shaped Distribution

Back 35

Highest frequency occurs in middle and frequencies tail off to the left and right of the middle

Front 36

Skewed Distribution

Back 36

Tail to the right of peak is longer than the left side

Front 37

Skewed Left

Back 37

Tail to the left of peak is longerthan the right