Tabular and Graphical Methods M1A 2 Flashcards
A table that summarizes the number of items in each of several non-overlapping classes
Frequency distribution
What is a way to group the measurements into classes of a frequency distribution and display the data?
A histogram
After a histogram of data is made, what will the pattern of classes show you?
The shape of the distribution
What are the steps in formulating a frequency distribution?
- Find the classes
- Find the length
- Form non-overlapping classes of equal length
- Tally and count
5, Graph the histogram.
What is the formula to find the number of classes in a frequency distribution?
2^c > (or equal to) n
For example n= 50
For c = 6 2^6 = 64
For c= 5. 2^5 = 32
Pick 6 classes since 32 is less than the sample.
How do you find the length of a frequency distribution class?
Take the largest and smallest and subtract them and divide by the number of classes (found earlier)
Round to an easy number to count
If you get 8.677 as the length round it to 10
Makes the value applicable. If you’re measuring time use 10 not 12.
How do you get the lower and upper values of the length of a class on a frequency distribution?
The lower limit of the class is the smallest value
The upper limit of the first class is the smallest value + class length
In a histogram, the base x-axis represents what?
The height represents what?
A. The in a frequency histogram
B. The relative frequency is a relative frequency histogram.
The base represents: The class length
The height represents;
A. The in a frequency histogram
B. The relative frequency is a relative frequency histogram.
What are the common frequency distribution shapes?
Skewed to the right
Skewed to the left
Symmetrical
Frequency polygons are made by doing what?
When is it helpful?
Taking a frequency distribution and plot a point above each class midpoint at a height equal to the frequency of the class using a dot/line plot
Useful when comparing two or more distributions.
What is another way to summarize a distribution other than a frequency table?
Construct a cumulative distribution
Explain a cumulative distribution
It’s basically calculating a running total instead of counting like a frequency distribution
Do this by using the same number of classes, length, and boundaries. Then record the number of measurements that are less than the upper boundary of the class.
When is a cumulative distribution table useful?
How many days did we not break even?
What is a relative cumulative frequency table?
Creating a percentage from the amount in a class divide by the sample size.
What is a graph of a cumulative distribution where you plot a point at the upper class boundary at the height of the cumulative frequency and connect the points with Line segments
An Ogive
