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
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
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
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.
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
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
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
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
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.
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
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
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
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
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
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.
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
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
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
Supposed we wish to test H0: µ = 10 vs. H1: µ > 10 at the α = 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
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
The data given below are taken from two independent samples collected randomly. Claim: (mu)1 > (mu2)2, alpha = 0.10, sample statistics: x1 (bar) = 500, s1 = 30, n1 = 100 x2 (bar) = 510, s2= 30, n2 = 75 What is the value of test statistics?
1) Test to see if four population means are the same or different. Assume the populations are normally distributed and have equal variances. Use the formal hypothesis-testing model. State the conclusion in statistical terms and in conversational English. Use the ANOVA table below. ANOVA Source of Variation SS df MS F
See the attached file. 1. To illustrate a production or marketing example: A company stats that is produces cookies with 50 chocolate chips per cookie. A sample of 36 cookies has an average of 49 chips with a standard deviation of 5 chips. Do we have a problem with our advertising claim of 50 chips per cookie (assume a confide
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 65%. A random sample of 175 patients who use this new drug is selected, and 96 of them find relief from depression. Based on these data, can we reject the
Does bread lose its vitamins when stored? Small loaves of bread were prepared with flour that was fortified with a fixed amount of vitamins. After baking, the vitamin C content of two loaves was measured. Another two loaves were baked at the same time, stored for three days and then the vitamin C content was measured. The units
1.A study with 36 observations had a mean of 70. Assume that the standard deviation is 12. Make a diagram that illustrates the effect of the confidence level on the width of the interval. Use 80%, 90%, 95% and 99%. Summarize what the diagram shows. 2.Computers in some vehicles calculate various quantities related to performa
An industrial plant wants to determine which of two types of fuel, electric or gas ... (Please see the attached file).
Loretta, who turns this year, has heard that the mean systolic blood pressure among the ...Please see the attached file.
A researcher studying stress is interested in the blood pressure measurements of chief executive officers (CEOs) of major corporations. He believes that the mean systolic blood pressure, μ, of CEOs of major corporations is less than 136 mm Hg, which is the value reported in a possibly outdated journal article. He plans to perfo
An auditor reviewed 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 aver