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    Hypothesis Testing

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    Significance Levels and Mean Signs

    Two boats, the Prada (Italy) and the Oracle (U.S.A.), are competing for a spot in the upcoming America's Cup race. They race over a part of the course several times. Below are the sample times in minutes. At the .05 significance level, can we conclude that there is a difference in their mean times? Boat Times (minutes) Prada (

    Standard Deviations - Clark Heter

    Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day-shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers s

    Level of Significance - White Industries

    The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes. Using

    variable analysis for data collections

    Choose a variable. Before collecting the data, decide what a likely average might be, then complete the following: a. Write a brief statement of purpose of the study b. Define the population c. State the hypotheses for the study d. Select an a value e. State how the sample was selected f. Show the raw data g. Decid

    Null and Alternative Hypotheses: How Decisions Are Made

    If John Smith is charged with a crime under the U.S. legal system and is brought to trial, what are the null and alternative hypotheses that the judge, the jury, and the prosecution must work under? If the jury decides in favor of John Smith does this mean that he has been proven innocent? What about if the jury finds against hi

    Hypothesis Testing: One-tailed and Two-tailed Testing

    I've been trying to understand the differences between one tailed and two tailed testing, t and z testing and p value. I think I understood #5 but need some help with #18, 23 and 44. 18. The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the

    Calculating Upper and Lower Control Limits

    A particular magazine typically has 65% subscription renewals. A new advertising campaign is introduced to see if this can be increased. To monitor renewals, a sample of 300 subscribers is taken each month to see what percentage renew their subscription. What are the upper and lower control limits for a control chart for the pro

    Consequences of Type I and Type II Errors

    You are a water quality tester, working for the EPA. You are testing the water in a stream just below the point where a major manufacturing company runs water from its plant into the stream. In particular, you are testing for the presence of a pollutant that is supposed to be held at a mean level of 10 ppm. You test the follo

    Z-Statistic, T-Statistic and P-value

    1. We have now studied two statistics Z and t. Compare and contrast the use of these two statistical tests, with particular attention to the quantity and quality of the data we use in each test. Is one test better than the other? 2. In research the concept of p value is useful to interpret the results of a hypothesis test.

    Statistics - highway mileage obtained from 20 automobiles

    The data to the left are the highway mileage obtained from 20 automobiles of the same make and model driven under normal conditions by 20 different owners. a. The sticker on the automobile claims that cars of this type get an average of 30 miles per gallon. However the average of these 20 autos is only 28.6 miles per gallon.

    A statistics question

    Dear: I need help with the following sample question. Many thanks! Could you offer me related data and detailed explanations to the sub-questions so that I can attack similar problems? Thanks! The question: We will run a regression to test whether the Random Walk Model describes daily adjusted closing prices for S

    Statistic problems - The null and alternate hypothesis

    #1 The null and alternate hypothesis: Null hypothesis : (MU)population mean^1 = (MU) population mean^2 Alternate hypothesis: (MU)population mean^1/=(MU) population mean^2 A random sample of 15 observations from the first population revealed a sample mean of 350 and a sample standard deviation of 12. A random sample

    Statistics Questions

    Please see attached file for full problem description. Chapter 10 For Exercises 1 & 3 answer the questions: (a) Is this a one- or two-tailed test? (b) What is the decision rule? (c) What is the value of the test statistic? (d) What is your decision regarding H0? (e) What is the p-value? Interpret it. 1. The following in

    ANOVA problems

    Please see attached file for full problem description. 1- At LLD Records, some of the market research of college students is done during promotions on college campuses, while other market research of college students is done through anonymous mail, phone, internet, and record store questionnaires. In all cases, for each new C

    Hypothesis Testing - Dozenol

    The nighttime cold medicine Dozenol bears the label indicating the presence of 600 mg of acetaminophen in each fluid ounce of drug. The Food and Drug administration randomly selected 98 one ounce samples and found that the mean acetaminophen is 575 mg, whereas the standard deviation is 55 mg. Use a 21% significance level and tes

    Statistics Review - Multiple Choice - Analysis of variance

    1. Variance is... A. The average of the squared deviation from the mean. B. A measure of variability of data values about the mean. C. A measure of dispersion. D. All of the above. F. None of the above. 2. Analysis of variance means... A. We compute the variances of the variables observed in the study.

    Testing of hypothesis for proportion

    1-Testing for categories with different proportions. Here are the observed frequencies from four categories; 5,10,10,20. Assume that we want to use a 0.05 significance level to test the claim that the four categories have proportions of 0.20, 0.25, 0.25and 0.30, repectively a. What is the null hypothesis? b. What are the expec

    Computer-interactive Data Analysis

    1-Refer to the table below (Computer-interactive Data analysis) that lists the number of years that U.S president and popes and British monarch (since 1690) lived after their inauguration, election, or coronation. Determine whether the survival times for the three groups differ. See attachment for data. 2q-Archaeology: Skull

    Compare two discounted plans

    Using the attached data sheet to determine whether the discounted plan is superior to the non-discounted plan. Each pair of customers was chosen from the same block in the district. The data represents the number of days before the customer pays the bill. Provide a 95% confidence interval for the difference between the sample m

    State Hypothesis and Test Statistics

    Attached data sheet represents the hours of work by professors at the university by academic level and professional degree. It has been discovered that the level information may be corrupted. Assume the academic level is erroneous and analyze the data using only known correct information. Use the six-step approach to analyze thi

    Determining Differences in Defect Levels

    The Allbest software company owns two computer-manufacturing plants. Each plant produces the Ultimate computer model. Plant measurement has determined that 28 out of 452 tested computers at Plant A were defective and that 21 out of 505 tested at plant B were defective. Is there cause for concern that the defect levels at these t

    Determine whether there is differences among four tire brands

    A Tire Company must determine which of four tire brands supplies the most amount of tire wear. It has been decided that all four tires are to be placed on each of eight cars. This design should allow us to compare tires without having differences in cars affect the comparison. Determine whether there is differences among the