"TRUE-FALSE. Write ‘True’ if the statement is correct and ‘false’ if it is incorrect.
________1. If the null hypothesis is stated that the average number of milligrams of sodium in a manufacturer’s can of soup is 200 mg, an appropriate alternative hypothesis is that the average number of milligrams of sodium exceeds 200 mg.
________2. If a calculated p value is relatively large, the implication is that the data are inconsistent with the null hypothesis such that it is likely that H0 should be rejected.
_______3. In order to conduct a lower-tail test of a population mean, the alternative hypothesis, HA, would be that the population exceeds a specific number.
______4. One way to determine whether a test is lower-tail or upper-tail is that a “<” sign is embedded in the alternative hypothesis of a lower-tail test and a “>” sign is embedded in the alternative hypothesis of an upper-tail test.
___ _____5. If the null hypothesis is actually true and your decision has been to reject it, you have committed a Type I error.
_______6. If you fail to reject the null hypothesis when it is actually true, then you have committed neither a Type I nor a Type II error.
________7. The larger the t statistic for an upper-tail test, the more likely the null hypothesis will be rejected.
________8. In order to compare the characteristics of two different populations, a sample should be extracted from each population.
________9. One of the major assumptions underlying ANOVA is that all the populations being studied in the experiment have the same variance.
________10. The z-test requires n-1 degrees of freedom to determine a critical value that separates the acceptance region from the rejection region.
MULTIPLE CHOICE (1 point each). Choose the best alternative and write the corresponding letter in the space provided.
__ _____11. Whenever a hypothesis is tested, the evidence that is used to determine validity comes from the:
A) decision B) conjecture C) sample data D) theory.
______12. A grocery store owner is interested in determining if the average weight of a package of ground beef sold in the store weighs one pound. An appropriate null hypothesis for this study is
a. H0: m = 1 lb
b. H0: m ¹ 1 lb
c. H0: m > 1 lb
d. H0: m < 1 lb
_______13. The appropriate Alternative hypothesis for an upper-tail test to determine if mean body weight of all the men who have joined a health club exceeds 185 pounds would be
a. HA: m ³ 185 lb.
b. HA: m > 185 lb.
c. HA: m £ 185 lb.
d. HA: m ¹ 185 lb.
______14. The shape of the F distribution is:
A) symmetric B) skewed right C) skewed left D) the same as the t distribution
_______15. The technique that is used to determine if three or more population means are equal by analyzing the variation in the data is known as:
A) chi-square test B) ANOVA C) correlation analysis D) regression analysis
_______16. The number of items in the sample that are free to vary is called:
A. test statistic B. critical value C. degrees of freedom D. p-value
_______17. Two independent samples are taken. The number in the first sample is 15 and the number in the second sample is 12. How many degrees of freedom are associated with the critical value?
A. 3 B. 27 C. 25 D. none
_______18. The condition for rejecting or accepting Ho is called:
test statistic B. critical value C. decision rule D. p-value
_______19. One of the following parametric tests does not require degrees of freedom:
A. F-test B. t-test C. z-test D. sign test
____ 20. In two ANOVA, experiments are repeated for each method of study to obtain additional data. This process is known as:
A. randomization B. replication C. factorization D. treatment
E. experimental design
Problem Solving (5 points).
Solve the following problem. Show your work wherever necessary (5 points)
21. The CFO of a company selling computer software through mega stores claims that average monthly profits throughout country will exceed $1 billion, with a standard deviation of $0.10 billion. A sample survey of software sales in 36 mega stores revealed an average monthly profit of $1.2 billion. You are asked to test the CFO’s claim by examining monthly profits from the sample mega stores using the Z-test. [use z-test, one population test for the mean- large sample].
A) State Ho and H1 for this claim.
B) Is this an upper tailed, lower tailed or two-tailed test? Why?
C) State the decision rule using ? = 0.05 significance level? [First find out tabular or critical z value. Note that the critical z value is different for a one-tailed and a two-tailed test).
D) Compute Z- statistic (computed z value).
E) What is the p-value? [To get the p-value for one-tailed test, first get the probability value in the standard normal table using the computed Z value. To get the p-value for two-tailed test multiple the result by 2]. Alternatively, you can use the following web link to compute the p-value. http://www.graphpad.com/quickcalcs/PValue1.cfm
F) What is your decision regarding Ho? ACCEPT or REJECT? Why?
G) What is your conclusion regarding the CFO’s claim? Was the claim correct or incorrect?