N1 100 n2 100 x1 38 x2 40

1. Assume that the data has a normal distribution and the number of observations is greater than fifty. Find the critical z value used to test a null hypothesis.

a = 0.05 for a two-tailed test. (Points : 5)
±2.575
1.764
±1.96
±1.645

2. Find the value of the test statistic z using z =

A claim is made that the proportion of children who play sports is less than 0.5, and the sample statistics include n = 1671 subjects with 30% saying that they play a sport. (Points : 5)
3.38
16.35
-33.38
-16.35

3. Use the given information to find the P-value. Also, use a 0.05 significance level and state the conclusion about the null hypothesis (reject the null hypothesis or fail to reject the null hypothesis).
The test statistic in a right-tailed test is z = 0.52. (Points : 5)
0.6030; fail to reject the null hypothesis
0.3015; fail to reject the null hypothesis
0.3015; reject the null hypothesis
0.0195; reject the null hypothesis

4. Use the given information to find the P-value. Also, use a 0.05 significance level and state the conclusion about the null hypothesis (reject the null hypothesis or fail to reject the null hypothesis).
The test statistic in a two-tailed test is z = -1.63. (Points : 5)
0.1032; fail to reject the null hypothesis
0.0516; reject the null hypothesis
0.0516; fail to reject the null hypothesis
0.9484; fail to reject the null hypothesis

5. Formulate the indicated conclusion in nontechnical terms. Be sure to address the original claim.
A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO, p, is less than 2 in every ten thousand. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, state the conclusion in nontechnical terms. (Points : 5)
There is sufficient evidence to support the claim that the true proportion is less than 2 in ten thousand.
There is sufficient evidence to support the claim that the true proportion is greater than 2 in ten thousand.
There is not sufficient evidence to support the claim that the true proportion is greater than 2 in ten thousand.
There is not sufficient evidence to support the claim that the true proportion is less than 2 in ten thousand.

6. Assume that a hypothesis test of the given claim will be conducted. Identify the type I or type II error for the test.
A medical researcher claims that 6% of children suffer from a certain disorder. Identify the type I error for the test. (Points : 5)
Reject the claim that the percentage of children who suffer from the disorder is different from 6% when that percentage really is different from 6%.
Reject the claim that the percentage of children who suffer from the disorder is equal to 6% when that percentage is actually 6%.
Fail to reject the claim that the percentage of children who suffer from the disorder is equal to 6% when that percentage is actually 6%.
Fail to reject the claim that the percentage of children who suffer from the disorder is equal to 6% when that percentage is actually different from 6%.

7. Assume that a hypothesis test of the given claim will be conducted. Identify the type I or type II error for the test.
A cereal company claims that the mean weight of the cereal in its packets is 14 oz. Identify the type I error for the test. (Points : 5)
Reject the claim that the mean weight is 14 oz when it is actually greater than 14 oz.
Fail to reject the claim that the mean weight is 14 oz when it is actually different from 14 oz.
Reject the claim that the mean weight is 14 oz when it is actually 14 oz.
Reject the claim that the mean weight is different from 14 oz when it is actually 14 oz.

8. Find the P-value for the indicated hypothesis test.
In a sample of 47 adults selected randomly from one town, it is found that 9 of them have been exposed to a particular strain of the flu. Find the P-value for a test of the claim that the proportion of all adults in the town that have been exposed to this strain of the flu is 8%. (Points : 5)
0.0048
0.0024
0.0262
0.0524