Minitab Instructions for Chapter 6 Technology Exercise

Windmill at Richland (Question 1)

Gathering the Data

The following example assumes that you were assigned "March". You should replace that with whatever month you were given to work with. Do not work with the current month, make sure the month is completely over before collecting data. You should be collecting data for the last two times your month has completely occurred.

  1. Visit the National Weather Service's archive page at http://www.weather.gov/climate/index.php?wfo=ilx.
  2. Chose the Preliminary Climatology Data (CF6)
  3. Choose the Decatur Airport
  4. Choose Archived Data
  5. Select the latest month and year for the month you were given. In this example, it would be March 2005 since March 2006 isn't over yet.
  6. Click Go.
  7. Record the "AVG SPD" for the Wind from column 10 for each of the days in March 2005. While you're at it, you might as well go ahead and collect the "AVG" for the temperature from column 4 because you'll need it for question 2.
  8. Click the Back button and choose March 2004 and Go
  9. Record the "AVG SPD" for the Wind from column 10 for each of the days in March 2004.

Entering the Data into Minitab

  1. Label the first column as wind
  2. If you happened to gather the temperature data, then label the second column as temp
  3. Enter the data into the appropriate columns

Graphical Summary

  1. Choose Stat / Basic Statistics / Graphical Summary
  2. Select the Wind variable
  3. Click OK
  4. Copy and paste the graph into Word

Confidence Interval

  1. Choose Stats / Basic Statistics / 1 Sample T
  2. The samples are in the wind column
  3. Click Options and make sure the confidence level is set correctly
  4. Click OK

The confidence interval will be given in parentheses under the heading "95% CI". You should write it in inequality notation; for example, if Minitab says (5.62333, 7.31215), then you should write 5.62333 mph < μ < 7.31215 mph.

Average Daily Temperature (Question 2)

If you already collected the temperature data for question 1, then you can skip straight to the Confidence Interval section.

Gathering the Data

The following example assumes that you were assigned "March". You should replace that with whatever month you were given to work with.

  1. Visit the National Weather Service's archive page at http://www.weather.gov/climate/index.php?wfo=ilx.
  2. Chose the Preliminary Climatology Data (CF6)
  3. Choose the Decatur Airport
  4. Choose Archived Data
  5. Select the latest month and year for the month you were given. In this example, it would be March 2005 since March 2006 isn't over yet.
  6. Click Go.
  7. Record the "AVG" for the temperature from column 4.

Entering the Data into Minitab

  1. Label an empty column as temp
  2. Enter the data into the temp column.

Graphical Summary

  1. Choose Stat / Basic Statistics / Graphical Summary
  2. Select the temp variable
  3. Click OK
  4. Copy and paste the graph into Word

Confidence Interval

  1. Choose Stats / Basic Statistics / 1 Sample T
  2. The samples are in the temp column
  3. Click Options and make sure the confidence level is set correctly
  4. Click OK

The confidence interval will be given in parentheses under the heading "95% CI". You should write it in inequality notation; for example, if Minitab says (74.3824, 77.6821), then you should write 74.3824 °F < μ < 77.6821 °F.

Normal Average Temperature

Visit the Weatherbase at http://www.weatherbase.com/. Do a search for "Decatur, IL" and find the average temperature for your month.