Chapter 2: Descriptive Statistics and Analytics-- Tabular and Graphical Methods Flashcards
T or F: visualizing our data helps us to understand data easily, and see trends/outliers.
True
T or F: With qualitative data, we can count this data and put in different categories. This data can be summarized using a frequency distribution.
True
a table that summarizes the number of items in each of several non-overlapping classes; is a useful summary that makes our data easier to understand
frequency distribution (look at pic in camera roll of frequency distribution)
________ frequency summarizes the proportion of items in each class.
relative
What is the formula to calculate relative frequency?
Frequency / total (or nā total # of observations)
What is the formula to calculate percent frequency?
Relative frequency x 100
What is the formula to calculate and assign degree of pie slice for a pie chart?
Relative frequency x 360
The sum of RELATIVE frequency is always equal to ______.
1
The sum of PERCENT frequency is always equal to _______.
100%
From frequency data, we can make what two kinds of charts?
Bar charts and pie charts
T or F: Bar charts/graphs must have spaces between bars to indicate that each class is separate from each other.
True
a vertical or horizontal rectangle represents the frequency for each category; height can be frequency, relative frequency, or percent frequency
bar chart
a circle divided into slices where the size of each slice represents its relative frequency or percent frequency
pie chart
a bar chart having the different kinds of defects listed on the horizontal scale; tells us how many errors/defects we have in our data
Pareto chart (look at camera roll for pic of pareto chart)
T or F: A pareto chart is a chart that can be made from quantitative data.
False; QUALITATIVE data
In a pareto chart:
- bar height represents the ______ of occurrence
- bars are arranged in (increasing/decreasing) height from left to right
- sometimes augmented by plotting a _________ percentage point for each bar
- frequency
- decreasing
- cumulative
A dot plot is used for (quantitative/qualitative data).
quantitative
A histogram can be made for (qualitative/quantitative) data.
quantitative
a graphical display of a frequency distribution, relative frequency distribution, or percentage frequency distribution. It divides measurements into classes and graphs the frequency, relative frequency, or percentage frequency for each class.
histogram
What are the 5 steps to build a histogram?
- Find the number of classes (formula= 2^k > or equal to n); (n= total number of observations, k= number of classes, which tells us the number of bars we need to build in histogram)
- Find the class length (length of our bars)
- Form non-overlapping classes of equal width (take lowest number and keep adding class length)
- Tally and count (frequency)
- Graph the histogram
What is the formula for finding the number of classes for building a histogram?
Formula = 2^k > (or equal to) n
n = total # of observations
k = # of classes (tells us the number of bars we need to build in histogram)
(look over example 2.2 in notes for histogram example notes)
T or F: Anything to the power of 0 is 1.
True
The number of classes (or bars in a histogram) is represented by the letter ____.
K
What is the formula for calculating class length (length of our bars in a histogram)?
Class Length = (largest value in our data - smallest value in our data) / classes (or k)