1. Open a blank Excel file and create a grouped frequency distribution of the maximum daily temperatures for the 50 states for a 30 day period. Use 8 classes.
2. Add midpoint, relative frequency, and cumulative frequency columns to your frequency distribution.
3. Create a frequency histogram using Excel. You will probably need to load the Data Analysis Add in within Excel. If you do not know how to create a histogram in Excel, view the video located at: http://www.youtube.com/watch?v=_gQUcRwDiik. Or a simple bar graph will also work.
If you cannot get the histogram or bar graph features to work, you may draw a histogram by hand and then scan or take a photo (your phone can probably do this) of your drawing and email it to your teacher.
4. Create a frequency polygon in Excel (or by hand). For help, view http://www.youtube.com/watch?v=IDnnXMLdmS0
5. A. Do any of the temperatures appear to be unrealistic or in error? If yes, which ones and why.
B. Explain how this affects your confidence in the validity of this data set.
Use the MIN and MAX functions in Excel to find the lowest and highest temperatures. This is shown in the Data tab.
Min = 47
Max = 111
Since the required number of classes is 8, compute the following:
Computed Class width = (111 - 47) / 8 = 8
Since the Computed Class width is an integer, use the next highest integer as the class width.
Class width = 9
Start the lowest class limit below 47. We will start at 45. Add 9 to each lower class ...
An Excel file satisfying all the requirements is attached. Explanations are provided for question 5.