Is there a relationship between wing length (mm) and wing beat frequency (Hz) among hummingbirds? In one study, researchers measured the wing lengths and wing beat frequencies of 12 hummingbirds.3 The following are basic summaries and a plot of the 12 data values.

(a) If the circled point was removed from this dataset, would the value of the sample correlation increase in magnitude, decrease in magnitude, or stay about the same? Briefly explain.
(b) The residual SD for all these data (including the points in the circle and triangle) is se = 2.40 Hz. If the point in the triangle were removed, would the residual SD increase, decrease, or stay about the same? Briefly explain.

Transcribed Image Text:

Variable Wing length (mm) Wingbeat frequency (Hz) .858 5.4176 Mean SD 39.4034 11.0090 r-0.9061 50 45 40 20 30 40 50 Wing Length (mm)