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Hypothesis Testing

Signifigance level

Number 8 A coffee manufacturer is interested in whether the mean daily consumption of regular-coffee drinkers is less than that of decaffeinated-coffee drinkers. Assume the population standard deviation for those drinking regular coffee is 1.20 cups per day and 1.36 cups per day for those drinking decaffeinated coffee. A rand

Statistics problems: Analysis method, probability, time intervals

The following information is for Questions 2. It is an open secret that airlines overbook flights, but I have just learned recently that bookstores underbook (I might have invented this new term.) textbooks.......... To make a long story short, our UMUC designated virtual bookstore, MBS Direct, routinely, as a matter of bu

Validity of test with difference sample sizes

2. A Wall Street Journal article suggests that age bias is becoming an even bigger problem in the corporate world. In 2001, an estimated 78% of executives believed that age bias was a serious problem. In a 2004 study by ExecuNet, 82% of the executives surveyed considered age bias a serious problem. The sample size for the 2004 s

Test Airport baggage scanning machine claims of 580 bags per hour

The manufacturer of an airport baggage scanning machine claims it can handle an average of 580 bags per hour. At alpha (?) = .01, would a sample of 18 randomly chosen hours with a mean of 525 and a standard deviation of 45 support the manufacturer's claim? Do both by hand and with Excel. Note- Use a 0.05 level of significance

Statistics Problems: Test for mean, proportion, paired samples, independence

See attached file for clarity of the tables included. 1. ONE SAMPLE HYPOTHESIS TEST FOR MEAN: A bowler who has averaged 196 pins in the past year is asked to experiment with a ball made of a new kind of material. If he rolls 25 games with the new ball, averaging 204 pins with a standard deviation of 24.9, can one conclude

Statistics: Identify the test statistice, critical value, conclusion, p value

1. A coin mint has a specification that a particular coin has a mean weight of 2.5g. A sample of 39 coins was collected. Those coins have a mean weight of 2.49382g and a standard deviation of 0.01581g. Use a 0.05 significance level to test the claim that this sample is from a population with a weight equal to 2.5g. Do the coins

9.26 Airport baggage scanning machine can average 530 bags per hour

9.26 The manufacturer of an airport baggage scanning machine claims it can handle an average of 530 bags per hour. (a) At ± = .05 in a left-tailed test, would a sample of 16 randomly chosen hours with a mean of 510 and a standard deviation of 50 indicate that the manufacturer's claim is overstated? (b) Why might the ass

Canning factory mean weight of 8 oz cans from Line A and Line B

5. Shipments of meat, meat by-products, and other ingredients are mixed together in several filling lines at a canning factory. Operations managers suspect that, although the mean amount filled per can of food is usually stable, the variability of the cans filled in line A is greater than that of line B. The following data from

Hypothesis Testing of Mean: Shopping Time

1. An article in Baltimore Sun claimed that the typical supermarket trip takes a mean of 22 minutes. Suppose that in an effort to test this claim, you select a sample of 50 shoppers at a Baltimore City Giant. The mean shopping time for the sample of 50 shoppers is 25.36 minutes, with a standard deviation of 7.24 minutes (estimat

Hypothesis Testing: Mean life for a shipment of lightbulbs

The quality-control manager at a light bulb factory needs to determine whether the mean life of a large shipment of light bulbs is equal to 375 hours. The population standard deviation is 100 hours. A random sample of 64 light bulbs indicates a sample mean life of 350 hours. a. At the 0.05 level of significance, is there eviden


Section 7.1 : Introduction to Hypothesis Testing 1. State the claim mathematically. Then write the null and alternative hypothesis. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. (References: Definition of a statistical hypothesis on page 365, example 1 on page 366 and example 3 on page 371;

BioStatistics Risk Factors: HIV Infection

A study was conducted looking at risk factors for HIV infection among intravenous drug users enrolled in a methadone program. The data given below were presented regarding the presence of HIV antibody among 120 non-Hispanic white subjects by total family income as assessed by blood testing at one point in time. Group

The Procedure to Test the Efficacy of Drugs

Two drugs (A,B) are compared for the medical treatment of duodenal ulcer. For this purpose, patients are carefully matched on age, sex, and clinical condition. The treatment results based on 200 matched pairs show that for 89 matched pairs both treatments are effective; for 90 matched pairs both treatments are ineffective; for 5

Hypothesis Testing

Independent random samples taken on two university campuses revealed the following information concerning the average amount of money spent on textbooks during the fall semester. University A University B Sample Size 50

Hypothesis tests on two populations

Problem 3 for Unit 10: Hypothesis Tests on two populations The Management of Discount furniture designed an incentive plan for its Salespeople.To evaluate this innovative plan, 12 sales persons were selected at random and their weekly sales before and after the plan were recorded. The paired data is: Before: 408, 377, 506, 518

Entomologist: Insects and Pheromone

An entomologist is studying the effect of a chemical sex attractant (pheromone) on insects. Several insects are released at a site equidistant from the pheromone under study and a control substance. If the pheromone has an effect, more insects will travel towards it rather than towards the control. Otherwise, the insects are equ

The solution to Hypothesis Testing of Mean & Proportion

1. A certain brand of Green Energy light bulbs was advertised as having an average illumination life-span of 2,500 hours. A random sample of 50 bulbs burned out with a mean life-span of 2,470 hours and a sample standard deviation of 140 hours. With a 0.05 level of significance, is the sample mean less than the advertised mean

Statistics Research and Evaluations: American Insurance Institute, Univ of Toledo

See attached file for table to problem 1. 1. The president of the American Insurance Institute wants to compare the yearly costs of auto insurance offered by two leading companies. He selects a sample of 15 families, some with only a single insured driver, others with several teenage drivers, and pays each family a stipend

Investigated race and equality of access to clinical trials

Researchers investigated the issue of race and equality of access to clinical trials. The table below shows the population distribution and the numbers of participants in clinical trials involving lung cancer (Based on data from "Participation in Cancer Clinical Trials," by Murthy, Krumholz, and Gross, Journal of the American Me

Testing of Hypothesis and Production Levels

Flash Jolt, a manufacturer of camera equipment, annually introduces new models in the fall of the year. At the conclusion of the Christmas season, retail dealers are contacted regarding their stock on hand of each piece of equipment. It has been discovered that unless 47% of the new equipment ordered by the retailers in the fall

Weight Reducers International: Determine the p-value

A new weight-watching company, Weight Reducers International, advertises that those who join will lose, on average, 10 pounds the first two weeks with a standard deviation of 2.8 pounds. A random sample of 50 people who joined the new Weight reduction program revealed the mean loss to be 9 pounds. At the .05 level of significanc

Statistics: Compare effectiveness of splinting versus surgery for carpal tunnel

A randomized trial was designed to compare the effectiveness of splinting versus surgery in the treatment of carpal tunnel syndrome. Results, given in the below table, are based on evaluations made one year after treatment. Using a 0.05 level of significance (? = 0.05), test the claim that success is independent of the type o