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    Hypothesis Testing

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    Determining Type I Error

    When you are using statistics to decide between two hypothesis, I believe that you have to allow for the possibility of error. You have committed a Type one error if you have rejected the hypothesis tested when it was true. A type I error occurs when one rejects the null hypothesis when it is true, and a type II error occurs whe


    A coin was flipped 60 times and came up heads 38 times. At the .10 level of significance, is the coin biased toward heads? Show decision rule and calculations. (b) calculate a p-value and interpret it.

    Hypothesis Testing ...

    The web-based company Oh Baby! Gifts has a goal of processing 95% of its orders on the same day they are received. If 485 out of the next 500 orders are processed on the same day, would this prove that they are exceeding their goal, using alpha =.025.

    Hypothesis Testing ...

    An auditor received 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was $275.66 with a standard deviation of $78.11. (a) At the 5 percent level of significance, does this sample prove a violation of the guideline that the ave

    Statistics - Right Tail P-value

    I am having major problems identifying formulas, assigning values, & recognizing symbols. This is because I had the 1st class in 2006, and this 2nd class should have followed immediately, but the academic counselors chose to assign other classes first. Now, I remember very little, & the instructor advises that I need to be ref

    Hypothesis Testing explained in this solution

    9.54 Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard

    Testing hypothesis

    A statistician was testing the following hypotheses: Ho: μ = 500 vs. Ha: μ ≠ 500. The p-value approach was to be used. A sample of size 49 gave a sample mean of 508. Given that σ = 30 2, and α = 0.01, find the p-value, and write your conclusion.

    Hypothesis testing: Athletics, Fishing

    Hypothesis Testing: For both problems answer the following. a) What is the level of significance? State null and alternate hypothesis. b) What sampling distribution will you use? do you think the sampling size is sufficiently large? Explain, What is the value of the sample test statistics? c) Find p-value of the test sta

    Hypothesis testing: Red Blood Cells, Glucose

    For problems 1-2 please provide the following information. a) What is the level of significance? State the null and alternate hypothesis. Will you use left-tailed or right tailed test? b) What sampling distribution will you use? Explain your rational for your choice of sampling distribution. What is the value of the sample

    Hypothesis Test: Difference Between Population Proportions

    It is asserted that a greater proportion of males (= x 1 ) contribute to charity than females (= x 2 ). A survey of male and female contributors to charity showed that of 900 males surveyed, 86 contributed to charity, and of 1200 females surveyed, 107 contributed to charity. Assume the sample statistics are from random, independ

    Question about Statistics: Hypothesis Testing of Political Persuasions

    You are curious about whether the professors and students at your school are of different political persuasions, so you take a sample of 20 professors and 20 students drawn randomly from each population. You find that 10 professors say they are conservative, and 6 students say they are conservative. Is this a statistically signi

    Hypothesis testing and Level of Significance

    Please provide the following information for the following 3 problems: a) What is the level of significance? State the null and alternate hypothesis. b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. What is the value of the sample test statistics? c) Find the

    Hypothesis testing for Chrysler Concorde Acceleration problem

    Chrysler Concorde Acceleration. Consumer reports stated that the mean time for a Chrysler Concorde to go from 0 to 60 miles per hour was 8.7 seconds. a) If you want to set up a statistical test to challenge the claim of 8.7 seconds what would you use for the null hypothesis? b) The town of Leadville, Colorado has an elevat

    Scatter Diagram

    Make a scatter diagram of the scores, describe in words the general pattern of correlation, if any; figure the correlation coefficient figure whether the correlation is statistically significant (use the .05 significance level, two-tailed); explain the logic of what you have done, writing as if you are speaking to someone who ha

    Multiple Choice Questions in Statistics

    1. For the hypothesis test, , with n1 = 10 and n2 = 10, the F-test statistic is 2.56. At the 0.01 level of significance, we would reject the null hypothesis. TRUE FALSE 2. If the endpoints of a confidence interval for the difference between a pair of treatment means are both positive numbers, then the

    Large Sample Hypothesis Test: Comparing Two Means

    A study conducted by the research department of a pharmaceutical company claims that the annual spending (per person) for prescription drugs for allergy relief,is greater than or equal to the annual spending (per person) for non-prescription allergy relief medicine. A health insurance company conducted an independent study and c

    Difference of proportion of annual income

    Past records suggest that the mean annual income,of teachers in state of Texas is greater than or equal to the mean annual income,of teachers in Virginia. In a current study, a random sample of 25 teachers from Texas and an independent random sample of 25 teachers from Virginia have been asked to report their mean annual income.

    Critical value for hypothesis testing

    The mean life of a battery used in a digital clock is 305 days. The lives of the battery follow normal distribution. The battery was recently modified to last longer. A sample of 20 of the modified batteries had a mean life of 311 days with a standard deviation of 12 days. The level of significance is .05. What would be your cri

    Hypothesis Test for a Population Proportion

    A decade-old study found that the proportion, of high school seniors who believed that "getting rich" was an important personal goal was 70% . A researcher decides to test whether or not that percentage still stands. He finds that, among the 240 high school seniors in his random sample, 184 believe that "getting rich" is an impo

    Test the hypothesis about the population mean

    Finance: P/E of Stocks. The price to earnings ratio(P/E) is an important tool in financial work. A random sample of 14 large U.S. banks gave the following P/E ratios. 24, 16, 22, 14, 12, 13, 17 22, 15, 19, 23, 13, 11, 18 The sample mean is xbar = 17.1( = sign is wavy). Generally speaking, a low P/E " value" or bargain sto

    Hypothesis Testing of Manufacturing Bottles

    1. In a bottling process, a manufacturer will lose money if the bottles contain either more or, less than is claimed on the label. The quality manager of a plant is interested in testing whether the mean ounces of catsup per family size bottle differ from the label by amount of 20 ounces. A sample of 9 bottles yields a mean fil

    Population mean

    Hypothesis test for the population mean: t test A college professor claims that the entering class this year appears to be smarter than entering classes from previous years. He tests a random sample of 17 of this year's entering students and finds that their mean IQ score is115 , with standard deviation of 14. The college rec

    Applied Statistics in Business Economics:Water on an Airline

    Is the water on your airline flight safe to drink? It is not feasible to analyze the water on every flight, so sampling is necessary. In August and September 2004, the Environmental Protection Agency (EPA) found bacterial contamination in water samples from the lavatories and galley water taps on 20 of 158 randomly selected U.S.

    Rejecting the Null Hypothesis: One-Tailed and Two-Tailed Test

    Suppose that we observe a random sample size n from a normally distributed population. If we are able to reject H0:µ = µ in favor of a two-tailed alternative hypothesis at the 10% significant level, is it true that we can definitely reject H0 in favor of the appropriate one-tailed alternative at the 5% significant level? Why o

    Hypothesis Testing 9. Consider the following hypothesis test: Ho:u > 20 Ho:u < 20 A sample of 50 provided a sample mean of 19.4. The population standard deviation is 2. a. Compute the value of the test statistic. b. What is the p-value? c. Using a = .05, what is your conclusion? d. What is the rejection rule using the critical value? What is your conclusion?

    Please see the attached file. 9. Consider the following hypothesis test: Ho:u > 20 Ho:u < 20 A sample of 50 provided a sample mean of 19.4. The population standard deviation is 2. a. Compute the value of the test statistic. b. What is the p-value? c. Using

    Hypothesis tests ...

    The MacBurger restaurant chain claims that the waiting time of customers for service is normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 signi

    Hypothesis Testing at Different Population Means

    Supposed we wish to test H0: µ = 10 vs. H1: µ > 10 at the &#945; = 0.05 significant level. Furthermore, supposed that we observe values of the sample mean and sample standard deviation when n=40 that do not lead to the rejection of H0. Is it true that we might reject H0 if we observed the same values of the sample mean and sam

    Hypothesis Testing: Improving Gas Mileage

    To test whether a fuel additive improves gas mileage, investigators measured the gas mileage (in miles per gallon) of nine cars with and without the fuel additive. At a level of α = 0.10, can it be concluded that the additive improved gas mileage ? The results are shown below. Car 1 2 3 4 5 6 7 8 9 Gas mileage w