Hypothesis testing for mean and variance.
Utilize the following to answer 1 through 3
A psychological researchers has a theory that predicts women will tend to carry more cash than men. A random sample of Ersatz University students revealed that 16 females had a mean of $22.30 in their wallets with a standard deviation of $3.20, even as 6 males had a mean of $17.30 with a standard deviation of $9.60.
1. The researcher's hypothesis would lead us to perform a
A. right-tailed test
B. left-tailed test
C. two-tailed test
D. None of the above
2. The test statistic for the researcher's main hypothesis is
3. At α = 0.05, the degrees of freedom for the researcher's main hypothesis would be
C. 5 to 15
4. A corporate analyst is testing whether inventory turnover has increased. Inventory turnover in six randomly-chosen product distribution centers (PDCs) is shown.
The critical value at α = 0.05 is
5. Analysis of variance is a technique used to test
A. difference between two variances
B. difference between more than two variances
C. difference between a population mean and a given value
D. difference between two or more means
6. Three bottles of wine are tasted by three experts. Each rater assigns a rating (scale is from 1 = terrible to 10 = superb).
Which test would you use for the most noticeable hypothesis?
A. t-test for independent means
B. one-factor ANOVA
C. two-factor ANOVA without replication
D. two-factor ANOVA with replication
7. In a analysis of variance test, the ratio of the mean square between groups to the mean square within groups follows a
A. normal distribution
B. F distribution
C. Chi-square distribution
D. Student's t distribution
8. Sound levels are measured at random moments under typical driving conditions for various full-size truck models. The ANOVA results are shown below.
The test statistic to compare the means is