OMIS 1050 WEEK 3

What is data visualization?

visual data representation study

What is data visualization’s use?

visually convey data / info

What is grouped data?

unsummarized data

What is a grouped data synonym?

raw data

What is grouped data?

frequency distribution data

What is frequency distribution?

data interval & frequency summary

What is the only allowable nominal data calculation?

count variable value frequency

What is a frequency distribution table?

category & count table

What is a relative frequency distribution table?

category & proportion table

What is a relative frequency synonym?

proportion

What are the frequency distribution graphical display techniques?

• bar chart

• pie chart

What is a bar chart?

graph

• parallel bars with proportional frequency length

What is a pie chart?

graph

• circle divided into slices with proportional frequency size

What is the most important interval/ratio graphical method?

histogram

Why is the histogram a powerful graphical technique?

• summarize interval data

• explain probability

What is a histogram?

graph

• value range display broken into group

What are histogram uses?

• graph large quantitative data set

• get initial data distribution overview

What is on the histogram x-axis?

class interval

What is on the histogram y-axis?

frequency

What is OGIVE?

cumulative frequency polygon

What is on the OGIVE x-axis?

class endpoint

What is on the OGIVE y-axis?

cumulative frequency

Where are dots plotted on each OGIVE class?

endpoint

When is OGIVE’s use?

• see running total

What is Sturges’ Rule?

class number guide summarizing data

What are the Sturges’ Rule formulas?

• 1 + 3.3(log n)

• 1 + (ln n)/(ln 2)

What is the range formula?

max value - min value

What is the class width formula?

range / class number

What does Excel call classes?

bins

What is the Excel bin value?

max class value

What does a histogram skewed left look like?

What does a symmetric / unimodal histogram look like?

What does a histogram skewed right look like?

What does a uniform histogram look like?

What does a bimodal histogram look like?

What does a multimodal histogram look like?

How do you create an Excel histogram?

Data → Data Analysis → Histogram → select data set in “Input Range” & select bin set in “Bin Range” & toggle “Chart Output”

How do you remove Excel histogram gaps?

Select a bar → Right click → Press “Format Data Series” → bring “Gap Width” to 0%

What is the keyboard shortcut to paste a column in a new worksheet?

Enter

What function returns the set amount?

=COUNT

How do you classify bins when creating an Excel histogram the long way?

FROM	TO
MIN	MIN + class width
{previous TO cell}	{previous TO cell} + $class$width

What is a 2 nominal variable chart method?

cross-tabulation

What is cross-tabulation?

process producing 2D table displaying 2 variable frequencies

What are some 2 nominal variable graph methods?

• clustered bar chart

• stacked bar chart

• 3D bar chart

• side-by-side pie chart

• scatter plot

What is a scatter plot?

2D graph plotting 2 numerical variables

What is a scatter plot’s use?

examine possible variable relationship

What is on the scatter plot x-axis?

independent variable

What is the scatter plot y-axis?

dependent variable

What does a scatter plot with positive linear relationship look like?

What does a scatter plot with no relationship look like?

What does a scatter plot with a negative linear relationship look like?

What does a scatter plot with a negative nonlinear relationship look like?

What does a scatter plot with a nonlinear concave relationship look like?

True or False: Negative nonlinear relationships can be concave.

True

True or False: Nonlinear concave relationships have to be positive.

False

What is time series data?

data gathered at intervals over time

What is the easiest way to visualize time series data?

line chart

How do you create an Excel histogram the short way?

Select column → Insert → Statistical Chart → Histogram

What’s the disadvantage of creating an Excel histogram?

• might have incorrect class width / quantity

How do you create an Excel scatter plot?

Select columns → Insert → X Y (Scatter) Chart → Scatter

How do you create an Excel time series graph?

Delete date label → Select columns → Insert → Line Chart → Line