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
Propose a 2-sample z-test of a population mean and identify it as either an independent test or a dependent test. Provide an example in simplest terms.
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
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
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;
Flip a coin 30 times and record the results. A fair coin should land on heads 50% of the time, which is the claim that we will use for our hypothesis. My results after flipping the coin: 17 heads and 13 tails My hypothesis would be: HO: p=0.5 Ha: p not = to 0.5 Where p represents the proportion of heads. Please he
A physician's health study of the effectiveness of aspirin in the reduction of heart attacks was begun in 1982 and completed in 1987 (see C. Hennekens et al., "Findings from the Aspirin Component of the Ongoing Physician's Health Study," The New England Journal of Medicine 318 (January 28, 1988): 262-264). Of 11,037 male medica
PROBLEM 4 The director of human resources at a large firm is comparing the distance traveled to work by employees in their office in downtown Atlanta with the distance for those in the downtown Jacksonville office. A sample of 21 Atlanta employees showed they travel a mean of 452 miles per month, with a sample standard deviati
Statistics and Hypothesis Testing: Take out dinners for individuals living alone; mean distance traveled to work.
PROBLEM 2 A marketing firm recently studied the number of times men and women who live alone that buy takeout dinners in a month. Two independent samples were taken one with 50 men and 55 women. The mean is 34.51 for men with a standard deviation of 3.48 and a mean of 29.44 with a standard deviation of 2.86. Conduct a two ta
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
An investigator wishes to study the effect of cigarette smoking on the development of myocardial infarction (MI) in women. A sample of 2000 disease-free current smoking women and 100 disease-free ex-smoking women, aged 50-59, are identified in 1996, and the incidence of MI between 1996 and 1998 is noted at follow-up visits 2 yea
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
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
In a random sample of 400 employees of a local company, 180 were female. a. At 95% confidence using the critical value approach, determine if the proportion of females in the company is significantly less than 50%. b. At 95% confidence using the p-value approach, test to determine if the proportion of females in the compan
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
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
At Kelsey High School, Mrs. Oâ??brien noted that the students were waiting too long in line for their lunches. After collecting some data, Ms. Oâ??brien determined the mean wait time was 10 minutes. She felt this time period was excessive and she instituted new procedures to streamline the process. One month later, a sample
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
Conduct a hypothesis test analysis to determine if there is a statistical difference between the ages of the sexes in the group.
Part A - Ask 10 people from a particular group (coworkers, students, civic group, etc.) what ages they are. Get at least 3 from each sex (i.e. male/female). Conduct a hypothesis test analysis to determine if there is a statistical difference between the ages of the sexes in the group. Explain your results. Use alpha = .05.
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
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
One day, you notice your 6' 2" roommate's size 12 shoes and comment, "I think height and foot size are correlated". You're somewhat surprised (and irked) by his response, "I think short people have big mouths." You decide to test your hypothesis; you find five people and record their heights (in inches) and shoe sizes. Calculate
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
The experimental group has mean of 38, control group has mean of 35. The standard deviations are 3 and 5, respectively. At the 5% level, what is the conclusion? The 20 in the experimental group had extra class time, the 30 in the control group did not.
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
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
The company has been experiencing increased shipping damage costs. Your team has been instructed to conduct a two-sample test to determine if shipping damages are equal for packages equal to or below 15 pounds (Package A) vs. packages greater than 15 pounds (Package B). The CEO must report to the Board of Directors if the ta
Please view MSWord attachment, which is an example of how this task should be. http://www.wholefoodsmarket.com/company/press-releases.php 1. What kind of business (industry / area of commerce) is the company involved in? 2. What kind of statistics information did you find? List them if there's more than one kind. Descr
Define (a) parameter, (b) estimator, (c) sampling error, and (d) sampling distribution. Explain the difference between sampling error and bias. Can they be controlled? Name three estimators. Which ones are unbiased? Explain what it means to say an estimator is (a) unbiased, (b) efficient, and (c) consistent. State th