The National Institute of Mental Health reported in the past that 20 of adult Americans suffer from a certain psychiatric disorder. A researcher would like to assess if the psychiatric disorder rate has been on the rise (that is, is currently higher than 20). A random sample of 80 adult Americans undergo an examination and 20 resulted in having a psychiatric disorder. Is this sufficient evidence to
suggest the rate has significantly
increased at a 5 significance level?
The z-statistic for the hypothesis test is
z = 1.12. What is the corresponding
p-value for the test?
1.1.12
2.0.13
3.0.84
4.0.26
Q. 2The National Institute of Mental Health reported in the past that 20 of adult Americans suffer from a certain psychiatric disorder. A researcher would like to assess if the psychiatric disorder rate has been on the rise (that is, is currently higher than 20). A random sample of 80 adult Americans undergo an examination and 20 resulted in having a psychiatric disorder. Is this sufficient
evidence to suggest the rate has
significantly increased at a 5
significance level? Which of the
following are the appropriate
hypotheses for this research question?
1.H0: p 0.25 versus Ha: p < 0.25
2.H0: = 0.25 versus Ha: > 0.25
3.H0: p > 0.20 versus Ha: p 0.20
4.H0: p = 0.20 versus Ha: p > 0.20
Q. 3A two-tailed hypothesis test is performed at the = 0.05 level. A critical value of z(0.025) = 1.96 is used to assess the significance of a test statistic, z = -1.81. Which is the correct inference?
1.Fail to reject the null hypothesis
2.Reject the null hypothesis
Q. 4What is the critical value for a one-tailed z-test for an alternative hypothesis that is stated as a less than at the = 0.02 level?
1.-2.33
2.-2.05
3.2.33
4.2.05
Q. 5In order to check the calibration of an automatic filling machine a sample is taken to assess the statement that the true fill is 12 oz. Which of the following is the most appropriate alternative hypothesis given this situation?
1. H : = 12 oz
2. H : > 12 oz
3. H : < 12 oz
4. H : 12 oz
Q. 6The relationship between Type I error, , and Type II error, , given a constant sample size is
1.they are equal.
2.as increases, decreases.
3.as increases, increases.
4.they are not related.
Q. 7The basic premise of hypothesis testing is to assume a status quo statement and examine sample information to assess the validity of the original statement. In order to no longer believe in the validity of the status quo statement, the sample statistic would need to be _____ to the population parameter.
1.unusual compared
2.similar in value
Q. 8Which of the following results in a Type I error if the null hypothesis, the mean tread life of a tire produced by the ABC company is 24,000 miles ( = 24,000), is tested?
1.The ABC company does produce tires that have a mean of 24,000 miles but the data suggested that the mean was not 24,000 miles.
2.The ABC company does produce tires that have a mean of 24,000 miles and the data suggested that the mean was 24,000 miles.
3.The ABC company does not produce tires that have a mean of 24,000 miles but the data suggested that the mean was not 24,000 miles.
4.The ABC company does not produce tires that have a mean of 24,000 miles but the data suggested that the mean was 24,000 miles
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