Statistics Test 3 Prof. VanderHoff Spring 2004
All work must be shown on exam to receive credit.
1[10] Test the null
hypothesis that the mean = 17 Use .05
significance level, a two tail test and the following data: sample size=9;
sample mean=15; sample standard deviation=4
2. [15] Test the hypothesis
that the mean before equals the mean after. Use .10 significance level and the
following data:
|
before |
after |
|
|
25 |
15 |
|
|
12 |
5 |
|
|
7 |
13 |
|
|
9 |
3 |
|
|
18 |
5 |
|
|
|
|
|
3 [10] Test the hypothesis
that the proportion of students who like stats=.30 Use .05 significance level
and a two tail test. In a survey of 80
students, 34 students like statistics.
4. [20] Test the hypothesis
that gender and preference for presidential candidates are independent. Use .05 significance level and the following
data:
|
|
Bush |
|
|
Kerry |
|
|
Nader |
|
|
|
|
men |
40 |
|
|
10 |
|
|
0 |
|
|
|
|
women |
80 |
|
|
50 |
|
|
20 |
|
|
|
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5[12] Test the hypothesis
that the proportion of men who support Bush equals the proportion of women who support
Bush. Use .05 significance level, a two
tail test and the following data:
|
numbers |
men |
women |
|
surveyed |
120 |
80 |
|
Support
Bush |
90 |
70 |
|
|
|
|
6 [13] Test the null
hypothesis that the mean for men is greater than or equal to the mean for
women. Use .05 significance level, a
one tail test and the following data:
|
sample |
women |
men |
|
Mean |
90 |
85 |
|
Standard
deviation |
8 |
10 |
|
number |
32 |
50 |
7 [10] Test the null
hypothesis that the mean = 120. Use .05
significance level, a two tail test and the following data: sample size=81;
sample mean=113; sample standard deviation=18
8. [20] Test the hypothesis
the means of groups a, b, c, and d are equal.
Use .05 significance level.
|
group |
a |
b |
c |
d |
|
mean |
80 |
90 |
70 |
60 |
|
variance |
20 |
10 |
15 |
5 |
|
n |
10 |
10 |
10 |
10 |