2.6
Collins temperature data (Data file: ftcollinstemp) The data filegives the mean temperature in the
fall of each year, defined as Sep-tember 1 to November 30, and the mean temperature in the following
winter, defined asDecember 1 to the end of February in the following calendar year,in degrees Fahrenheit, for Ft. Collins, CO (Colorado ClimateCenter, 2012). These data cover the time period from 1900 to 2010.The question of interest is: Does the average
fall temperature predict theaverage
wintertemperature?
2.6.1 Draw a scatterolot of the response versus thepredictor and describe any pattern you might see in the plot.
2.6.2 Use statistical software to fit the regression ofthe response on the predictor. Add the fitted line to your graph.Test the slope to be 0 against a two-sided alternative, andsummarize your results.
2.6.3 Compute or obtain from your computer output thevalue of the variability in winter explained by fall and explainwhat this means.
2.6.4 Divide the data into 2 time periods, an earlyperiod from 1900 to 1989 , and a late period from 1990 to 2010. Youcan do this using the variable year in the data file. Are theresults different in the two time periods?
