OIS 2340 Midterm 3
In a two-tailed hypothesis test the area in each tail of the rejection region is equal to α. T/F
False
To calculate beta requires making a "what if" assumption about the true population parameter, where the "what-if" value is one that would cause the null hypothesis to be false. T/F
False
A major issue facing many states is whether to legalize casino gambling. Suppose the governor of one state believes that more than 55% of the state's registered voters would favor some form of legal casino gambling. However, before backing a proposal to allow such gambling, the governor has instructed his aides to conduct a statistical test on the issue. To do this, the aides have hired a consulting firm to survey a simple random sample of 300 voters in the state. Of these 300 voters, 175 actually favored legalized gambling. State the appropriate null and alternative hypotheses.
H0 : p ≤ 0.55 Ha : p > 0.55
The makers of Mini-Oats Cereal have an automated packaging machine that can be set at any targeted fill level between 12 and 32 ounces. Every box of cereal is not expected to contain exactly the targeted weight, but the average of all boxes filled should. At the end of every shift (eight hours), 16 boxes are selected at random and the mean and standard deviation of the sample are computed. Based on these sample results, the production control manager determines whether the filling machine needs to be readjusted or whether it remains all right to operate. Use α = 0.05. Establish the appropriate null and alternative hypotheses to be tested for boxes that are supposed to have an average of 24 ounces.
H0 : μ = 24 ounces Ha : μ ≠ 24 ounces
According to CNN business partner Careerbuilder.com, the average starting salary for accounting graduates in 2008 was at least $47,413. Suppose that the American Society for Certified Public Accountants planned to test this claim by randomly sampling 200 accountants who graduated in 2008. State the appropriate null and alternative hypotheses.
H0 : μ ≥ $47,413 HA : μ < $47,413
Which of the following statements is true? Alpha and beta are directly related such that when one is increased the other will increase also. The alternative hypothesis should contain the equality. The decision maker controls the probability of making a Type I statistical error. Alpha represents the probability of making a Type II error.
The decision maker controls the probability of making a Type I statistical error.
In hypothesis testing, the null hypothesis should contain the equality sign. T/F
True
Hypothesis testing and confidence interval estimation are essentially two totally different statistical procedures and share little in common with each other. T/F
False
If a hypothesis test is conducted for a population mean, a null and alternative hypothesis of the form: H0 : μ = 100 HA : μ ≠ 100 will result in a one-tailed hypothesis test since the sample result can fall in only one tail. T/F
False
The Adams Shoe Company believes that the mean size for men's shoes is now more than 10 inches. To test this, it has selected a random sample of n = 100 men. Assuming that the test is to be conducted using a .05 level of significance, a p-value of .07 would lead the company to conclude that its belief is correct. T/F
False
The following is an appropriate statement of the null and alternate hypotheses for a test of a population mean: T/F H0: μ < 50 HA : μ > 50
False
Choosing an alpha of 0.01 will cause beta to equal 0.99. T/F
False Alpha + Beta never = 1
Waiters at Finegold's Restaurant and Lounge earn most of their income from tips. Each waiter is required to "tip-out" a portion of tips to the table bussers and hostesses. The manager has based the "tip-out" rate on the assumption that the mean tip is at least 15% of the customer bill. To make sure that this is the correct assumption, he has decided to conduct a test by randomly sampling 60 bills and recording the actual tips. State the appropriate null and alternative hypotheses
H0 : μ ≥ 15 Ha : μ < 15
If P> Alpha accept/reject null?
If P is low Null must go. Accept
The makers of Mini-Oats Cereal have an automated packaging machine that can be set at any targeted fill level between 12 and 32 ounces. Every box of cereal is not expected to contain exactly the targeted weight, but the average of all boxes filled should. At the end of every shift (eight hours), 16 boxes are selected at random and the mean and standard deviation of the sample are computed. Based on these sample results, the production control manager determines whether the filling machine needs to be readjusted or whether it remains all right to operate. At the end of a particular shift during which the machine was filling 24-ounce boxes of Mini-Oats, the sample mean of 16 boxes was 24.32 ounces, with a standard deviation of 0.70 ounce. Assist the production control manager in determining if the machine is achieving its targeted average at alpha = 0.05.
Process is running okay, do not reject H0
A local medical center has advertised that the mean wait for services will be less than 15 minutes. Given this claim, the hypothesis test for the population mean should be a one-tailed test with the rejection region in the lower (left-hand) tail of the sampling distribution. T/F
True
In conducting a hypothesis test where the conclusion is to reject the null hypothesis, then either a correct decision has been made or else a Type I error. T/F
True
The null and alternate hypotheses must be opposites of each other. T/F
True
When the decision maker has control over the null and alternative hypotheses, the alternative hypotheses should be the "research" hypothesis.T/F
True
When someone is on trial for suspicion of committing a crime, the hypotheses are: H0 : innocent HA : guilty Which of the following is correct? Type II error is convicting an innocent person. Type I error is convicting an innocent person. Type I error is acquitting a guilty person. Type II error is acquitting an innocent person.
Type I error is convicting an innocent person.
The power of a test is measured by its capability of: rejecting a null hypothesis that is true. not rejecting a null hypothesis that is false. not rejecting a null hypothesis that is true. rejecting a null hypothesis that is false.
rejecting a null hypothesis that is false.
If the p value is less than α in a two-tailed test, a one-tailed test should be used. the null hypothesis should not be rejected. the null hypothesis should be rejected. More information is needed to reach a conclusion about the null hypothesis.
the null hypothesis should be rejected.
A hypothesis test is to be conducted using an alpha = .05 level. This means: there is a maximum 5 percent chance that a true null hypothesis will be rejected. there is a 5 percent chance that the null hypothesis is true. there is a 5 percent chance that a Type II error has been committed. there is a 5 percent chance that the alternative hypothesis is true.
there is a 5 percent chance that the alternative hypothesis is true.
