Loading in 5 sec....

1.2 - Displaying quantitative data with graphsPowerPoint Presentation

1.2 - Displaying quantitative data with graphs

- 182 Views
- Uploaded on
- Presentation posted in: General

1.2 - Displaying quantitative data with graphs

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

(Histograms)

The most common graph of quantitative data.

(not the most convenient)

Classes: the intervals along the bottom axis.

These need to be of equal width

Frequency: the count of individuals of a class occurring

Relative frequency: the percent of the individuals in a class

(this is more useful, especially when you are comparing two sets of data with an unequal total of individuals)

- The following table represents the battings averages for the 25 Cincinnati Reds who have an at bat this time in the 2013 season.

- The following table represents the battings averages for the 29 Cincinnati Reds who have an at bat this time in the 2014 season.

1st - divide the range of data into class of equal width.

2nd - find the count and percent of individuals in each class.

3rd - label and scale your axes

4th - draw your histogram

What is the range of our data?

What would be a good class size to choose?

What are the classes?

Fill in a frequency table and a relative frequency table.

- 2013

- 2014

- Relative Frequency

- Relative Frequency

- Batting Average

- Batting Average

- Don’t forget your “SOCS!”

- The histogram shows that the batting ranged from __________

- The data appears to be _______ with a peak of _____ .

- The center of the data occurs around ______

- The _____ appear to be any outliers.

- www.whfreeman.com/tps4e

- 2. Don’t use the counts or percents as the data. Use the data to find the counts and percents for your graph.

- 3. Use percents instead of counts when comparing distributions with different numbers of observations.

- 4. Just because a graph looks nice, doesn’t mean it’s necessarily a meaningful display of data.
- (Excel is a terrible tool to use for statistical graphs)

1. Don’t confuse histograms and bar graphs

Histograms are for quantitative data

Bar graphs are for categorical data