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# Hypothesis Testing

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### Is there a difference in proportion?

10. The manager of a computer software company wishes to study the number of hours top executives spend at their computer terminals by type of industry. The manager selected a sample of five executives from each of three industries. At the .05 significance level, can she conclude there is a difference in the mean number of hours

### Stats

The production manager at Bellevue Steel, a manufacturer of wheelchairs, wants to perform a second analysis of the number of defective wheelchairs produced on the day shift and afternoon shift. A sample of the production from 6 day shifts and 8 afternoon shifts revealed the following number of defects. At the 0.05 significanc

### Hypothesis Testing

Hypothesis Testing for Proportions.

### Degrees of Freedom and Significance Level: Null Hypothesis

1. If I have a degree of freedom equal to 4 with a significance level of .01. Would there be enough evidence to support a claim with a test statistic equal to 13.5? Would this support or reject the null hypothesis if the null hypothesis supports the claim?

### Statistics : Critical Region and Null Hypotheses

The critical region or rejection region is the set of all values of the test statistic that causes what to the null hypothesis?

### Statistics : Hypothesis Testing, Test Statistic and Critical Region

Please help answer the following questions involving statistics. 1. Why do we use hypothesis testing? 2. What is a test statistic and how is it related to a critical value in hypothesis testing? 3. What is the critical region in hypothesis testing and why is it important?

### Civics Hypothesis Testing

1) The nationwide mean price for a 3-year old Honda civic is \$8,500 with a known standard deviation of \$600. You check the newspaper and find nine 3-year old Civics in San Francisco selling for an average price of \$9,000. You wonder whether the cost of Civics in San Francisco is higher than the rest of the nation. a) State yo

### Test with P-Value

1. To compare the current attitudes toward prayer in the schools, a survey was conducted in four southern California counties {see attached for results}. State your hypotheses and conduct a test for homogeneity of attitudes among the four counties concerning prayer in the schools. Use a P-value in your conclusion. It would N

### Hypothesis testing of tires and fuel economy

A taxi company manager is trying to decide if the use of radial tires instead of regular belted tires improves fuel economy. As a test, twelve cars are equipped with belted tires and the cars are driven over a prescribed test course. Without changing drivers the same cars were then equipped with the radial tires and driven once

### Test of hypothesis: difference between proportions

A survey was completed to estimate the proportion of residents in support of constructing a new football stadium, at tax payer expense, to accommodate an NFL team in the LA area. It was found that 71 of 100 LA city residents favored the construction while 78 of 135 residents in the rest of the county were in support. Determine i

### Research Methods / Statistics: 3. Four experimenters investigated the number of items recalled in a study of short-term memory when comparing some 25 year-old participants (Y) with some 65 year-old participants (O). (Use a two-tailed test.) a) Analyze the data as an independent samples design. b) Analyze the same data set as a matched pairs design.

See attachment for complete question. 3 Four experimenters investigated the number of items recalled in a study of short-term memory when comparing some 25 year-old participants (Y) with some 65 year-old participants (O). (Use a two-tailed test.) For this question you will be assigned data from one of these exp

### Psychology Research Methods / Stats - Analyze the Data

2. Pigeons were trained to peck to obtain food. During extinction, one group of 21 pigeons was given a drug that inhibits the protein metabolism necessary for memory, while another group of 21 pigeons was not. The rate of pecking was then analyzed (use a one-tailed test). Does the drug increase the pigeons' pecking behaviour?

### Design and Analysis of an Experiment Question

From time to time, one branch office of a company must make shipments to a certain branch office in another state. There are three package delivery services between the two cities where the branch offices are located. Since the price structures for the three delivery services are quite similar, the company wants to compare the d

### In testing a hypothesis using the X2 test, the theoretical frequencies are based on the

6. In testing a hypothesis using the X2 test, the theoretical frequencies are based on the a. null hypothesis. b. alternative hypothesis. c. normal distribution. d. None of the above. 7. If we wish to determine whether there is evidence that the proportion of successes is higher in group 1 than in group 2

### Health Study on Aspirin

US physicians, health study consisted of two randomized clinical trails in one. the first tested the hypothesis that 345 milligrams of aspirin taken every other day reduces mortality from cardiovascular disease. The second tested whether 50 mg B-carotene taken on alternate days decreases the incidence of cancer. 261,248 male phy

### Inference

1. A 4-day work week ensure that employees will have one more day that need not be spent at work. One possible result is a reduction in the average number of person leave days taken by employees on a 4-day work schedule. Do the data indicate that this is the case? use the p-value approach in testing to reach your conclusion.

### Test of hypothesis, p value, confidence interval, linear regression

1. The wages for middle managers in a certain industry are thought to be no more than \$45,000.00. A wage survey of 30 managers has a mean income of \$46,260.00. Test the hypothesis at a 1% significance level. Does it appear that the average annual income is greater than \$45,000.00? The population standard deviation is assumed

### A question about null hypothesis is included.

In a study in which null hypothesis has been rejected, we should be aware of the possibility of ________ alternative hypotheses, Type II Errors, change due to new observations, all are correct This question is posed.

### Multiple choice questions on testing of hypothesis

1.The power of a test is measured by its capability of a. rejecting a null hypothesis that is true. b. not rejecting a null hypothesis that is true. c. rejecting a null hypothesis that is false. d. not rejecting a null hypothesis that is false. 2. If an economist wishes to determine whethe

### experimental design research methods

This job talks about the randomized, pretest-posttest, control-group design nature of an experimental design.

### Experiment

This job lists characteristics of an experiment.

### Statistical Analysis - Background Music

A researcher had the idea that background music might enhance performance on a math test and that the effect of music might depend on whether an individual is a music lover or not. She selected 50 music lovers and 50 control participants who did not listen to music on a regular basis. Half of the participants from each group t

### Hypothesis testing for difference in mean

Using AIU's large database of survey responses (Database Attached) (keep in mind this database is your sample), you will begin testing hypotheses. Complete all of the following: 1. Test a hypothesis to see whether the average overall job satisfaction (in the population of all workers in the USA) is equal to 4.5 with a = .05.

### Multinomial, Negative Binomials and Hypothesis Testing

I have several questions I'm stuck on: 1. A production line produces good articles with probability .7, average ones with probability of .2, and defective ones with probability .1. Ten articles are selected. a) What is the probability of 8 good ones and 1 defective? b) What is the probability that there

### Statistic Problems and Harassment

Employers sometimes seem to prefer executives who appear physically fit...Here are the data...c) You should also hesitate to conclude that increasing fitness causes an increase in ego strength. Explain why?

### Null Hypothesis Sample Deviation Effects

2)Your company has recently changed suppliers of a certain raw material in an effort to reduce the number of defective units being produced at your plant. During the past year, the sampling has indicated a daily mean of 21.2 defective units. After testing the new suppliers raw materials for 30 days, it was found that the mean

### Null Hypothesis Level of Significance

1)According to company figures, the age of a first time customer is normally distributed with an average age of 29.8 years and a standard deviation of 4.5 years. The marketing department has designed a new advertising strategy and wants to determine if this has had any impact on the average viewing age. Since the new ad campai

### Computing the P-Value: The Iowa Department of Highways

An official of the Iowa Department of Highways wants to compare the useful life, in months, of two brands of paint used for striping roads. The mean number of months Cooper Paint lasted was 36.2 with a standard deviation of 1.114 months. The official review 35 road stripes. For King Paint, the mean number of months was 37.0 w

### One tailed test of hypothesis: difference between means

To evaluate the relative merits of two prosthetic devices designed to facilitate manual dexterity, an occupational therapist assigned 21 patients with identical handicaps to wear one or the other of two devices while performing a certain task. 11 patients wore device A and 10 wore device B. The researcher recorded the time each

### Test of hypothesis using dependent samples..

A group of 10 students was pretested before instruction and posttested 6 weeks of instruction with the following achievement scores: Student Before After Difference 1 14 17 3 2 12 16 4 3 20 21 1 4 8 10 2 5 11 10 -1 6 15 14 -1 7 17 20 3 8