Eliminate one magazine type that you now feel has a mean length different than the others. Redo the hypothesis test, testing that the remaining three means are statistically the same. Use a new solution sheet. Based on this test, are the mean lengths for the remaining three magazines statistically the same?
A researcher wants to know if the mean time (in minutes) that people watch their favorite news station are the same. Suppose that the table below shows the results of a study.
CNN
FOX
Local
45
15
72
12
43
37
18
68
56
38
50
60
23
31
51
35
22
Assume that all distributions are normal, the four population standard deviations are approximately the same, and the data were collected independently and randomly. Use a level of significance of 0.05.
df(n) = 2; df(d) = 14
4.08
0.0401
Reject the null hypothesis
There is sufficient evidence to conclude that the mean times are different.
Are the means for the final exams the same for all statistics class delivery types? The table below shows the scores on final exams from several randomly selected classes that used the different delivery types.
Online
Hybrid
Face-to-Face
72
83
80
84
73
78
77
84
84
80
81
81
81
86
79
82
Assume that all distributions are normal, the four population standard deviations are approximately the same, and the data were collected independently and randomly. Use a level of significance of 0.05.
Are the mean number of times a month a person eats out same for whites, blacks, Hispanics and Asians? Suppose that the table below shows the results of a study.
White
Black
Hispanic
Asian
6
4
7
8
8
1
3
3
2
5
5
5
4
2
4
1
6
6
7
Assume that all distributions are normal, the four population standard deviations are approximately the same, and the data were collected independently and randomly. Use a level of significance of 0.05.
df(n) = 3; df(d) = 15
0.8853
0.4711
Do not reject the null hypothesis
There is insufficient evidence to conclude that the mean number of times are different.
Are the mean number of daily visitors to a ski resort the same for the three types of snow conditions? Suppose that the table below shows the results of a study.
Powder
Machine Made
Hard Packed
1210
2107
2846
1080
1149
1638
1537
862
2019
941
1870
1178
1528
2233
1382
Assume that all distributions are normal, the four population standard deviations are approximately the same, and the data were collected independently and randomly. Use a level of significance of 0.05.
Is the variance for the amount of money, in dollars, that shoppers spend on Saturdays at the mall the same as the variance for the amount of money that shoppers spend on Sundays at the mall? Suppose that the table below shows the results of a study.
Saturday
Sunday
75
44
62
137
18
58
0
82
150
61
124
39
94
19
50
127
62
99
31
141
73
60
118
73
89
Assume that both distributions are normal. Use a level of significance of 0.05.
df(n) = 11; df(d) = 12
1.35
0.6090
Do not reject the null hypothesis
There is insufficient evidence to conclude that the variances are different.
Are the variances for incomes on the East Coast and the West Coast the same? Suppose that the table below shows the results of a study. Income is shown in thousands of dollars.
East
West
38
71
47
126
30
42
82
51
75
44
52
90
115
88
67
Assume that both distributions are normal. Use a level of significance of 0.05.
Abiotic factors are non living components of ecosystem.These include physical and chemical elements like temperature,light,water,soil,air quality and oxygen etc
