In the 2005 Major League Baseball season, a random sample of 10 American League teams' home runs showed a mean total of 175.3 with a standard deviation of 31.7. In the National League a random sample of 10 teams' home runs showed a mean of 159.6 with a standard deviation of 31.53. Is the difference in home runs between leagues s
Leave out questions 1, 3, 11 and 12. 1. The value of the z score in a hypothesis test is influenced by a variety of factors. Assuming that all other variables are held constant, explain how the value of z is influenced by each of the following: Increasing the difference between the sample mean and the original population mea
3) A consumer advocacy group is doing a large study on car rental practices. Among other things, the consumer group would like to do a statistical test regarding the mean monthly mileage of cars rented in the U.S. this year. The consumer group has reason to believe that the mean monthly mileage of cars rented in the U.S. this ye
1) The mean SAT score in mathematics is 488 . The founders of a nationwide SAT preparation course claim that graduates of the course score higher, on average, than the national mean. Suppose that the founders of the course want to carry out a hypothesis test to see if their claim has merit. State the null hypothesis H0 and the
The Web-based company Oh Baby! Gifts have a goal of processing 95 percent of its orders on the same day they are received. If 365 out of the next 375 orders are processed on the same day, would this prove that they are exceeding their goal, using α = .01? Explain your decision. AND At Oxnard University, a sample of 1
In the midst of labor-management negotiations, the president of a company argues that the company's blue-collar workers, who are paid an average of $30,000 per year, are well paid because the mean annual income of all blue-collar workers in the country is less than $30,000. That figure is disputed by the union, which does not b
14) Medical researchers interested in determining the relative effectiveness of two different drug treatments on people with a chronic mental illness established two independent test groups. The first group consisted of 9 people with the illness, and the second group consisted of 12 people with the illness. The first group recei
9) A decade-old study found that the proportion "P" of high school seniors who believed that "getting rich" was an important personal goal was 80% . A researcher decides to test whether or not that percentage still stands. He finds that, among the 235 high school seniors in his random sample, 182 believe that "getting rich" is
7) An electronics manufacturing process has a scheduled mean completion time of 75 minutes. It is claimed that, under new management, the mean completion time is less than 75 minutes. To test this claim, a random sample of 9 completion times under new management was taken. The sample had a mean completion time of 73 minutes an
5) The breaking strengths of cables produced by a certain manufacturer have a mean of 1775 pounds, and a standard deviation of 55 pounds. It is claimed that an improvement in the manufacturing process has increased the mean breaking strength. To evaluate this claim, 90 newly manufactured cables are randomly chosen and tested,
The manager of a driving school claims that the mean time taken to learn how to drive a car is 8 hours or less for all new drivers. A sample of 16 new drivers showed that the mean time taken by them to learn how to drive the car is 9.5 hours with a standard deviation of 1.5 hours. Test the manager's claim at the 1% significance
An experimental bumper was designed to reduce damage in low-speed collisions. This bumper was installed on an experimental group of vans in a large fleet, but not on a control group. At the end of a trial period, there were 12 repair incidents (a "repair incident" is an accident that resulted in a repair invoice) for the experim
I am doing a paper investigating whether a combination of behavioral therapy and medication is more successful in treating depression patients than medication alone. I need help in putting this paper together along with some references. I also need to address these questions: 1. Describe your selected research issue, problem,
In recent years major efforts have been made to standardize accounting practices in different countries; this is called harmonization. In an article in Accounting and Business Research, Emmanuel N. Emenyonu and Sidney J. Gray (1992) studied the extent to which accounting practices in France, Germany, and the United Kingdom are h
How do we decide whether to use a z test or a t test when testing a hypothesis about a population mean?
Give an example of a hypothesis test you could perform at work or at home. State what the Null and the Alternative hypotheses would be in your test. Explain how you would settle on a reasonable level of significance for your scenario. Also explain what the type I and II errors would be if you reached the incorrect conclusion in
Assume you are the manager of a paint manufacturing factory. Your company has received complaints from customers that the containers hold less than the amount printed on them. On the other hand, corporate management is concerned that the containers hold more than the standard amount. You assign a statistician to verify the claim
When doing hypothesis testing we have two ways of making a decision - the critical value method and the p-value method. While both give the same results in terms of determining whether to reject or not reject the null hypothesis, most statistical analysts prefer the p-value method. Describe the two methods and explain why the
1) Compute/answer the following about the variables "Balance" and "ATM", fr om the Century National Bank Data Set. a) Develop a scatter diagram that represents the question, do higher balances lead to higher usage of ATMs? b) The coefficient of correlation (interpret) c) The coefficient of determination (interpret) d) Is
In each case, identify the population parameter about which a claim is made, state the null and alternative hypotheses for a hypothesis test, and indicate whether the hypothesis test will be left-tailed, right-tailed, or two-tailed a. The manufacturer of a new model of hybrid car advertises that the mean fuel consumption i
The production line that packages boxes of raisins at a snack food manufacturer will be considered operating properly if the average weight of the boxes of raisins is 1.5 ounces with a standard deviation of 0.1 ounces. A random sample of 16 boxes showed an average weight of 1.45 ounces. 1. How can I find the null and altern
The manufacturer of a new antidepressant claims that, among all people with depression who use the drug, the proportion p of people who find relief from depression is at least 80% . A random sample of 215 patients who use this new drug is selected, and 170 of them find relief from depression. Based on these data, can we reject t
See the attached file. 2(a). In the context of hypothesis test, state what is meant by: (i). Type I error (ii). Type II error (iii). Power of the test What connections are there, if any, between them? (b). The sales and marketing team in motor business is investigating the quality of second hand cars. One indicator o
I Completed the first half, but I am struggling with the questions below. They are multiple choice. Objective: Apply hypothesis testing to different populations and samples in business research situations. 5. One characteristic of any Student's t distribution is a. It is right skewed. b. As n increases, the t-di
1. A researcher conducts an experiment comparing three treatment conditions. The data consist of n=20 scores for each treatment condition. a. If the researcher used an independent-measures design, then how many individuals were needed for the study and what are the df values for the F ratio? b. If the researcher used a repeate
A production line operates with a mean filling weight of 500 grams per container. Over filling or under filling presents a serious problem and when detected requires the operator to shut down the production line to readjust the filling mechanism. From past data, a population standard deviation = 25 grams is assumed. A quality co
2. A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the .10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree? Pin
MCQs for Statistics and Hypothesis Testing: New drug, tree trunk diameters, and money spent on business dinners.
If you choose to solve these problems, please show the steps and formulas used. 1. A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. At = .05, what is
1. Use a P- value to test the claim about the population mean μ using the given sample statistics. State your decision for α = 0.05 Claim: μ ≠ 230; Sample statistics: x (bar) = 216.5, s = 17.3, n = 48 = _ 2. If X =5.2, R =.3,and n=4, and if specifications are (4.6, 5.8), is the process capable? Show work.
1) Two gasoline additives will be tested to determine their impact on miles per gallon for passenger cars. In the experiment, each car was tested with both gasoline additives. Use a level of significance α = 0.05 and the rank sum test Wilcoxon test whether any significant difference in the two additives.