Module 4, Descriptive statistics for a single variable

Question 1

data

Answer 1

A set of values of qualitative or quantitative variables; pieces of data are individual pieces of information.

Question 2

numerical summary

Answer 2

A number used to describe a specific characteristic about a data set.

Question 3

box plots

Answer 3

A graphical rendering of the range and the first and third quartiles of a data set with the data set’s median in between.

Question 4

mode

Answer 4

The most frequent value in a dataset.

Question 5

median

Answer 5

The value or quantity lying at the midpoint of a frequency distribution.

Question 6

measures of spread

Answer 6

A number of measures used to determine the distance of data from the center of the data set, such as range and standard deviation.

Question 7

skewed distribution

Answer 7

A distribution that is not symmetrical but has a greater quantity of data on one side of the mean.

Question 8

normal distribution

Answer 8

A common type of distribution of data points that forms a bell shaped, symmetrical curve around the mean.

Question 9

valid data

Answer 9

Data that results from a test that accurately measures what it was intended to measure.

Question 10

dot plot

Answer 10

A graphical representation of data that plots the frequency of data along a horizontal line.

Question 11

scale

Answer 11

The relationship between units and their visual representation on a graph.

Question 12

graphical displays

Answer 12

Visual displays of data sets.

Question 13

pie chart

Answer 13

A graphical display that shows data in categories as percentages of a circle.

Question 14

stem plot

Answer 14

A visual representation of data in which individual data points are plotted to the right of a vertical line, or chart, and the left (the “stem”) shows the interval categories.

Question 15

bimodal

Answer 15

A description of a data set with two modes.

Question 16

data set

Answer 16

Any collection of numerical values, such as measurements, observations, or survey responses.

Question 17

qualitative data

Answer 17

Non-numeric information based on some quality or characteristic.

Question 18

outlier

Answer 18

An observation point that is significantly distant from the other observations in the dataset.

Question 19

measure of central tendency

Answer 19

A summary measure that is used to describe an entire set of data with one value that represents the middle or center of the data set’s distribution. There are three main measures: mean, median, or mode.

Question 20

shape

Answer 20

The outline of a set of data displayed on the coordinate axes.

Question 21

unimodal

Answer 21

A set of data having one mode.

Question 22

standard deviation

Answer 22

The measure on average of how far the data points are from the mean.

Question 23

skewed right

Answer 23

A skewed distribution where the long tail of the curve is on the positive side of the peak.

Question 24

categorical data

Answer 24

This type of data, also called qualitative data, consists of data values that can be sorted into groups or categories.

Question 25

bar chart

Answer 25

A graph that displays data that is distributed over groups or categories.

Question 26

range

Answer 26

The difference between the maximum and minimum values.

Question 27

minimum

Answer 27

The smallest value in a set.

Question 28

frequency distribution

Answer 28

A record of the number of times data occurs within a certain category.

Question 29

quartile

Answer 29

Values that divide a data set into four equally sized groups.

Question 30

multimodal

Answer 30

A description of a data set that has more than two modes.

Question 31

center

Answer 31

One of three measures that describe what is “normal” in a data set: mean, median, or mode.

Question 32

the Standard Deviation Rule

Answer 32

A standard proportion or percentage of data points that lie within each standard deviation away from the mean for a normal distribution.

Question 33

mean

Answer 33

Average, calculated by adding a series of elements in a data set together and dividing by the total number in the series.

Question 34

check sheet

Answer 34

A structured form or table that allows data to be collected by marking how often an event has occurred in a certain interval.

Question 35

symmetry

Answer 35

The quality of the data having the same shape on both sides of the mean.

Question 36

reliable data

Answer 36

Data is both consistent and repeatable.

Question 37

skewness

Answer 37

A measure of the degree to which a probability distribution “leans” toward one side of the average, where the median and mean are not the same.

Question 38

histogram

Answer 38

A graph that displays data through vertical bars that show the counts or numbers in each range.

Question 39

distribution

Answer 39

An arrangement of values that illustrates their frequency or occurrence.

Question 40

five-number summary

Answer 40

The minimum, first quartile, median, third quartile, and maximum. A box plot represents the five numbers in a five-number summary.

Question 41

maximum

Answer 41

The largest value in a set.

Question 42

statistics

Answer 42

The science that deals with the interpretation of numerical facts or data through theories of probability. Also, the numerical facts or data themselves.

Question 43

quantitative data

Answer 43

Data values that are numbers, representing quantities that can be counted or measured.

Question 44

interquartile range

Answer 44

The difference, in value, between the bottom and top 25 percent of the sample or population.

Question 45

skewed left

Answer 45

A skewed distribution where the long tail of the curve is on the negative side of the peak.

Question 46

Standard Deviation Rule

Answer 46

(68-95-99.7 Rule)
68% of data is within1 standard deviation of the mean
95% of data is within 2 standard deviations of the mean
99.7% of data is within 3 standard deviations of the mean

Question 47

How do you determine outliers?

Answer 47

Upper outlier
Q3 + (iqr * 1.5)=upper outlier

Lower outlier
Q1 - (iqr * 1.5)=lower outlier