People swam across Lake Ontario 52 times between 1974 and 2013 (www.soloswims.com). We might be interested in whether they are getting any I faster or slower. Here are the regression of the crossing Times (minutes) against the Year since 1974 of the crossing and the residuals plot:
Dependent variable is Time
R-squared = 1.2% s = 439.1
Variable Coefficient
Intercept €¦€¦€¦€¦€¦€¦€¦ 1213.423
Year since 1974 €¦€¦€¦€¦. 3.986

a) What does the R2 mean for this regression?
b) Are the swimmers getting faster or slower? Explain.
c) The outlier seen in the residuals plot is a crossing by Vicki Keith in 1987 in which she swam a round trip, north to south, and then back again. Clearly, this swim doesn't belong with the others. Would removing it change the model a lot? Explain.

Transcribed Image Text:

3000 2000 1000 0 10 20 30 40 50 60 Years Since 1974