Here are heart rates for a sample of 30 students before and after a class break. At α = .05, was
there a significant difference in the mean heart rate? (a) State the hypotheses. (b) State the decision
rule and sketch it. (c) Find the test statistic. (d) Make a decision. (e) Estimate the p-value and
interpret it. HeartRate
10.59 Emergency room arrivals in a large hospital showed the statistics below for 2 months. At α = .05,
has the variance changed? Show all steps clearly, including an illustration of the decision rule.
10.61 A certain company will purchase the house of any employee who is transferred out of state and
will handle all details of reselling the house. The purchase price is based on two assessments, one
assessor being chosen by the employee and one by the company. Based on the sample of eight assessments
shown, do the two assessors agree? Use the .01 level of significance, state hypotheses
clearly, and show all steps. HomeValue
Statistic October November
Mean arrivals 177.0323 171.7333
Standard deviation 13.48205 15.4271
Days 31 30
Note: Thanks to colleague Gene Fliedner for having his evening students take their own pulses before and after the 10-minute class break.
Heart Rate Before and After Class Break
Student Before After Student Before After
1 60 62 16 70 64
2 70 76 17 69 66
3 77 78 18 64 69
4 80 83 19 70 73
5 82 82 20 59 58
6 82 83 21 62 65
7 41 66 22 66 68
8 65 63 23 81 77
9 58 60 24 56 57
10 50 54 25 64 62
11 82 93 26 78 79
12 56 55 27 75 74
13 71 67 28 66 67
14 67 68 29 59 63
15 66 75 30 98 82
1 answer