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# Hypothesis Testing

### Test hypothesis for relationship between age group and communication preferred

USA Today reported on preferred types of office communication by different age groups. Suppose the results were based on a survey of 500 respondents in each age group. The results are cross-classified in the following table: Type of Communication Preferred AGE GROUP Group Face to Emails Others Total

### Statistics: Test if cocaine use by pregnant women produces low birth weight babies

Please show detailed solutions. Does cocaine use by pregnant women cause their babies to have low birth weight? To study this question, birth weights of babies of women who tested positive for cocaine/crack during a drug-screening test were compared with the birth weights for babies whose mothers either tested negative or we

### 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: Standards high-sulfur coal; New Hampshire Insurance; pay for union nurses

See attached file for format of answers. Number 5 A nationwide sample of influential Republicans and Democrats was asked as a part of a comprehensive survey whether they favored lowering environmental standards so that high-sulfur coal could be burned in coal-fired power plants. The results were: Republicans Democrats

### 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

### Statistics: Unit 7 MML Project: Light bulb life, killowatt hour usage, microwave repair

A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 950 hours. A random sample of 35 light bulbs has a mean life of 934 hours with a standard deviation of 80 hours. Do you have enough evidence to reject the manufacturer's claim? use a=0.04. (a) Identify the null hypothesis and a

### 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

### Statistics

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;

### 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

### 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

### BioStatistics: Effect of cigarette smoking on the development of myocardial infarction

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

### 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

### 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.

### 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

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

### Report on research of increased shipping damage costs

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