Start time: _______ End time: _______			Name: ___________________________
	Or, record elapsed time in minutes: __________
	Part V: LSRL Significance Test (32 points)
13.	In 1995, a sample of top male biathletes showed the following data for treadmill time to reach maximum heart rate versus time needed to ski 20 km. All times are in minutes.
		Treadmill	Ski
		7.7	71.0
		8.4	71.4
		8.7	65.0
		9.0	68.7
		9.6	64.4
		9.6	69.4
		10.0	63.0
		10.2	64.6
		10.4	66.9
		11.0	62.6
		11.7	61.7
	Here is some computer output related to the data set, with two values blacked out:
	The regression equation is ski = 88.8 − 2.33tread
	Predictor	Coef	Stdev		t-ratio	p
	Constant	88.796	●●●●●●		15.44	0.000
	tread	−2.3335	●●●●●●		−3.95	0.003
	s = 2.188       R-sq = 63.4%       R-sq(adj) = 59.3%
	Analysis of Variance
	Source	DF	SS		MS	F	p
	Regression	1	74.630		74.630	15.58	0.003
	Error	9	43.097		4.789
	Total	10	117.727
(a)	State the value of the slope: _____________
(b)	Interpret your answer to part (a) in the context of this problem.
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(c)	Compute a 90% confidence interval for the true value (population value) of the slope. Do not check assumptions here, since you will be doing that in part (d) anyway. Show work. If you need one of the blacked-out values, you can obtain it for a point if you raise your hand.

(d)	Is there evidence that the true population slope is negative? Use = 0.01 for this problem. Show all steps below, and write “OVER” if you need more room. This is a long problem.
BONUS	(1 point) Explain briefly why, in part (d), the true population slope is negative if and only if the true population r-value (what we call ) is also negative.
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