1) The statement that determines if the null hypothesis is rejected or not is called the
A. decision rule
B. critical value
C. test statistic
D. alternate hypothesis
2) What are the critical z-values for a two-tailed hypothesis test if the significant level = 0.01?
A. ± 2.58
B. ± 1.65
C. ± 2.33
D. ± 1.96
3) An independent consumer testing lab preformed a statistical test on 25 type-C alkaline batteries and calculated the mean life for a particular use before they failed was 22.5 hours. The distribution of the lives approximated a normal distribution. The standard deviation of the distribution was 1.1 hours. Information on the package states that the batteries should last 24 hours.
The test question was if this difference between the test statistics and the stated life of the battery was significant? The .05 significant level was selected for the test. Which is the correct statement?
A. The difference cannot be evaluated with this small of a sample.
B. The difference indicates that the batteries are not good.
C. The difference was not significant.
D. The difference was significant; the batteries do not meet the stated length of time.
4) K & S Construction, located in Phoenix, Arizona, is working on its business plan for the upcoming year. They did a study to determine if they should focus on building condominiums or individual houses. A building study, which had been conducted by the state, indicated that 60 percent of those families looking to buy a home in Arizona desired to buy a condominium. K & S Construction wanted to know if this figure applied to Phoenix. They collected a sample of 500 individuals that had expressed plans to buy a new home. The z-distribution was selected for this proportion test. The null hypothesis is p = 0.60 and the alternate is p ≠ 0.60. The significant level selected was .05. From the sample of 500, it was determined that 290 wanted to buy a condominium. What decision should be made regarding the null hypothesis?
A. Cannot accept nor reject it based on the information given
B. The test level of .05 is not acceptable
C. Reject it
D. Fail to reject it
5) In classical hypothesis testing, the test statistic is to the critical value what the ________________.
A. test statistic is to the p-value
B. level of significance is to the test statistic
C. critical value is to alpha
D. p-value is to alpha
6) A statistician was setting up a hypothesis test with a level of significance dictated by upper management. However, she was concerned that the test she wished to perform might have unacceptable large possibilities of Type II error, ß. Which of the following would solve this problem?
A. Convince upper management to use a smaller p-value.
B. Convince upper management to reduce the level of significance of the test.
C. Convince upper management to use a larger sample.
D. Convince upper management to use a larger p-value.
7) Thomas Delivery has a fleet of 24 trucks that are utilized for the companies; business. Electro-Lite, a manufacturer of spark plugs, claims that its spark plugs have an average life in excess of 25,000 miles. The purchasing agent at Thomas Delivery purchased 24 sets and found that the sample average life was 26,300 miles, the sample standard deviation was 1,500 miles, and the computed test statistic was t = 3.423. Based on these findings, at the 0.05 level, is there enough evidence to accept the manufacturer’s claim?
A. Electro-Lite claims are not supported by the test results.
B. Electro-Lite claims are supported; the spark plugs do exceed the mean of 25,000 miles.
C. Electro-Lite claims cannot be supported or denied with the test results.
D. Electro-Lite claims are just an advertising promotion.
8) A machine is set to fill the small size packages of Good and Better candies are packaged with 60 pieces of candies in each bag. Sampling results revealed: 3 bags of 61, 2 bags of 59, 1 bag of 58, and 2 bags of 62. How many degrees of freedom are there?
A. 9
B. 7
C. 1
D. 8
9) If the paired differences are normal in a test of mean differences, then the distribution used for testing is the
A. normal distribution
B. F distribution
C. Chi-Square
D. Student t distribution
10) Golf balls that are properly manufactured will have a rebound height of 42 inches when dropped by a testing machine from a height of 5 feet. The quality control inspector is concerned that a new manufacturing machine is not properly calibrated and that the resulting golf balls are falling short of the desired height. At random, 100 golf balls were selected for a test. The test results indicated that the rebound height was 41.6 inches with a standard deviation of 0.5. At the .05 significant level, what is the result of the test?
A. There is no significant difference.
B. A larger test sample is needed.
C. There is a significant difference; the golf balls are defected.
D. A decision regarding a significant difference cannot be made.
11) A recent study by College Stat Company reported a nationwide survey of college students determined that students spend 2 hours studying for each hour in the classroom. Professor Baker at State College wants to determine whether the time students spend at her college is significantly different from the national average of 2 hours. A random sample of 20 statistics students resulted in an average of 1.75 hours with a standard deviation of 0.24 hours. A t-test was conducted at the 5% level of significance. The calculated value of t was -4.03. What was Professor Baker decision?
A. Cannot make a decision at this time; more data is required.
B. Reject the alternative hypothesis statement.
C. Fail to reject the null hypothesis.
D. Reject the null hypothesis, the test statistic exceeds the critical value.
12) In a test for the equality of two variances (two-tailed), when the populations are normal, a 5% level of significance was used. Sample sizes were n1 = 13 and n2 = 10. The upper critical value for the test is
A. =FINV(0.05, 12, 9).
B. =FINV(1-0.025, 13, 10).
C. =FINV(0.025, 12, 9).
D. =FINV(0.025, 13, 10).
