Chapter 1 - Describing Graphs with Data Flashcards
a characteristic that changes or varies over time and/or for different individuals or objects under consideration
Variable
Hair color, white blood cell count, time to failure of a computer component, Apple stock price (over time) These are examples of?
Variables
the individual or object on which a variable is measured
Experimental Unit
results when a variable is actually measured on an experimental unit
a Measurement
A set of measurements called __, can be either a __ or a ___
data sample population
Each of these are an example of:
1) Hair color
2) Person
3) Brown, black, blonde, etc.
1) Variable 2) Experimental unit 3) Typical Measurements
Each of these are an example of: 1) Time until a light bulb burns out 2) light bulb 3) 1500 hours, 1535.5 hours, etc.
1) Variable 2) Experimental unit 3) Typical Measurements
One variable is measured on a single experimental unit
Univariate Data
Two variables are measured on a single experimental unit
Bivariate Data
More than two variables are measured on a single experimental unit
Multivariate Data
Types of Variables
1) Qualitative 2) Quantitative
Types of Quantitative Variables
a) discrete b) continuous
measure a quality or characteristic on each experimental unit.
Qualitative (categorical) Variables
measure a numerical quantity on each experimental unit
Quantitative Variables
if it can assume only a finite or countable number of values
Discrete Quantitative Variable
if it can assume the infinitely many values corresponding to the points on a line interval
Continuous Quantitative Variable
For each orange tree in a grove, the number of oranges is measured.
Quantitative discrete
For a particular day, the number of cars entering a college campus is measured.
Quantitative discrete
Time until a light bulb burns out
Quantitative continuous
Graphing Qualitative Variables 1) Qualitative Variables use a ___ ___ to describe: a) b)
1) Data Distribution a) WHAT VALUES of the variable have been measured b) HOW OFTEN each value has occurred
“How Often” can be measured in (3) ways
1) Frequency 2) Relative frequency = Frequency/n ( n=sample size) 3) Percent = 100 x Relative frequency
Relative Frequency Equation
Frequency/n ( n=sample size)
Percent Equation
100 x Relative Frequency
A single quantitative variable measured for different population segments or for different categories of classification can be graphed using?
a PIE or BAR chart
Dotplot how to make one?
Plots the measurements as points on a horizontal axis, stacking the points that duplicate existing points.
Dotplot for what type of data?
Quantitative data
Stem and Leaf Plots for what type of data?
Quantitative data
Stem and Leaf Plot 1) Divide each measurement into two parts: the __ and the __. 2) List the stems in a __, with a __ __ to their __. 3) For each measurement, record the __ __ in the __ __ as its __ __. 4) Order the leaves from __ to __ in each __. 5) Provide a __ to your coding.
1) Stem and the Leaf 2) In a Column, Vertical Line to their Right 3) Leaf portion, same row, matching stem 4) lowest to highest in each stem 5) key
1) A single quantitative variable measured over time is called a
2) It can be graphed using a __ or a ___ ___.
1) Time Series
2) Line or Bar Chart
Dotplot for the data set: 4, 5, 5, 7, 6

Stem and Leaf Plot for Data:
The prices ($) of 18 brands of walking shoes:
90 70 70 70 75 70 65 68 60
74 70 95 75 70 68 65 40 65

Which Shapes are each of these graphs:

1) mound shaped & symmetric (mirror image)
2) Skewed right: a few unusually large measurements
3) Skewed left: a few unusually small measurements
4) Bimodal: two local peaks
Strange or unusual measurements that stand out in the data set
Outliers
Relative Frequency Histogram
1) for what type of data set?
2) what type of graph
3) height of the bar shows?
4) hows it measured?
1) quantitative data
2) bar graph
3) the height of the bar shows “how often” measurements fall in a particular class or subinterval.
4) measured as a proportion or relative frequency
How to make a Relative Frequency Histogram

Relative Frequency Histograms
1) Divide the range of the data into __ ____ of equal length.
2) Calculate the __ __ of the subinterval as Range/number of subintervals.
3) Round the approximate __ up to a convenient value.
4) Use the method of __ __, including the __ endpoint, but not the __ in your __.
5) Create a statistical table including the __, their __ and __ __ .
1) 5-12 subintervals
2) approximate width
3) width
4) left inclusion, left, right, tally
5) subintervals, frequencies, relative frequencies
Relative Frequency Histogram
1) horizontal axis
2) vertical axis
1) subintervals
2) relative frequency
Relative Frequency Histograms
height of the bar represents?
PROPORTION of measurements falling in that class or subinterval
PROBABILITY that a single measurement , drawn at random from the set, will belong to that class