11.14: Solutions
( \newcommand{\kernel}{\mathrm{null}\,}\)
1.
mean = 25 and standard deviation = 7.0711
3.
when the number of degrees of freedom is greater than 90
5.
df=2
6.
a test of a single variance
8.
a left-tailed test
10.
H0:σ2=0.812;
Ha:σ2>0.812.
12.
a test of a single variance
16.
a goodness-of-fit test
18.
3
20.
2.04
21.
We decline to reject the null hypothesis. There is not enough evidence to suggest that the observed test scores are significantly different from the expected test scores.
23.
H0: the distribution of AIDS cases follows the ethnicities of the general population of Santa Clara County.
25.
right-tailed
27.
2016.136
28.
- 30.
a test of independence
a test of independence
34.
8
36.
6.6
39.
Smoking level per day African American Native Hawaiian Latino Japanese Americans White Totals 1-10 9,886 2,745 12,831 8,378 7,650 41,490 11-20 6,514 3,062 4,932 10,680 9,877 35,065 21-30 1,671 1,419 1,406 4,715 6,062 15,273 31+ 759 788 800 2,305 3,970 8,622 Totals 18,830 8,014 19,969 26,078 27,559 10,0450 Table 11.14.54 41.
Smoking level per day African American Native Hawaiian Latino Japanese Americans White 1-10 7777.57 3310.11 8248.02 10771.29 11383.01 11-20 6573.16 2797.52 6970.76 9103.29 9620.27 21-30 2863.02 1218.49 3036.20 3965.05 4190.23 31+ 1616.25 687.87 1714.01 2238.37 2365.49 Table 11.14.55 43.
10,301.8
44.
right
46.
- 48.
test for homogeneity
test for homogeneity
52.
All values in the table must be greater than or equal to five.
54.
3
57.
a goodness-of-fit test
59.
a test for independence
61.
Answers will vary. Sample answer: Tests of independence and tests for homogeneity both calculate the test statistic the same way ∑(ij)(O−E)2E. In addition, all values must be greater than or equal to five.
63.
true
65.
false
67.
225
69.
H0:σ2≤150
71.
36
72.
Check student’s solution.
74.
The claim is that the variance is no more than 150 minutes.
76.
a Student's t- or normal distribution
78.
- 48.