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# Hypothesis Testing

### Calculating Test Statistics and checking claim

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?

### Hypothesis Testing for Four Population Means with ANOVA Tables

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

### Hypothesis Testing to Increase Significance

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

### Performing a One-Tailed Test: Effectiveness of an Antidepressant

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

### Hypothesis Testing - Does bread lose its vitamins when stored? Small loaves of bread were prepared with ... (Please see the attached file)

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

### Determining the Confidence Interval and Hypothesis Testing

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

### Statistics - Null and Alternate Hypothesis

An industrial plant wants to determine which of two types of fuel, electric or gas ... (Please see the attached file).

### Null and Alternate Hypothesis

Loretta, who turns this year, has heard that the mean systolic blood pressure among the ...Please see the attached file.

### Blood Pressures: Null and Alternate Hypothesis and Type I Errors

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

### Small sample hypothesis test for a population mean

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

### Hypothesis test for a population proportion.

A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coined biased towards heads? Show your decision rule and calculations. (b) Calculate a p-value and interpret it.

### Quantitative Research Methods

1. Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the night shift than on the days shift. Assume the populations standard deviation for the number of units produced on the days shift is 21 and is 28 on the night shift. A sample of 54 day shift workers

### Hypothesis Testing Question

Does lovastatin (a cholesterol lowering drug) reduce the risk of heart attack? In a Texas study, researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (averge age 58). After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the inactive pill. a) state the appro

### Hypothesis Testing In Dallas some fire trucks were painted yellow (instead of red)to heighten their visibility. During a test period the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runds and had 4 accidents. At a=.01, did the yellow fire trucks have a significantly lower accident rate? a)state the hypothesis B) state the decision rule and sketch it c)find the sample proportions and z test statistic)make a decision e)find the p-value and interpret it f)if statistically significant, do you think the difference is large enough to be important? If so, to whom, and why? g)is the normality assumption fulfilled? Explain.

In Dallas some fire trucks were painted yellow (instead of red)to heighten their visibility. During a test period the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runds and had 4 accidents. At a=.01, did the yellow fire trucks have a significantly lower accid

### Estimation Procedures Handled

Why are proportions handled differently than means in estimating procedures?

### Small sample hypothesis test for a population mean

How tall are college hockey players? The average height has been 68.3 inches. A random sample of 14 hockey players gave a mean height of 69.1 inches. We may assume that x has a normal distribution with &#963; = 0.9 inch. Does this indicate that the populations mean height is different from 68.3 inches? Use 5% level of signi

### Statistical questions

1. Can the formal hypothesis testing approach be used for non parametric tests? a) How are parametric and nonparametric statistics different? b) How are parametric and nonparametric statistics similar?

### Test Statistics from Computer Generated Regression Model

Using observations on each variable, a computer program generated the following multiple regression model: If the standard errors of the coefficients of the independent variables are, respectively, and , can you conclude that the independent variable is needed in the regression model? Let and denote the coeffici

### Test Statistics of Consumer Products

A consumer products testing group is evaluating two competing brands of tires, Brand 1 and Brand 2. Tread wear can vary considerably depending on the type of car, and the group is trying to eliminate this effect by installing the two brands on the same random sample of cars. In particular, each car has one tire of each brand on

### Why is statistical significance not necessarily of practical important difference to a business decision? Give an example and explain. Why do statisticians play only a limited role in deciding whether statistical significance requires a business action?

Why is statistical significance not necessarily of practical important difference to a business decision? Give an example and explain. Why do statisticians play only a limited role in deciding whether statistical significance requires a business action?

### Hypothesis Testing of Garage and Township

Is there an association or correlation between the variables 'attached garage' and 'township.' Use the 0.05 significance level. Please see the attached file.

### Hypothesis Testing Problem ...

High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld sound meter. Noise level is defined as "Low" (under 88 decibels), "Medium" (88 to 91 decibels), or "High" (92 decibels or more). There

### Hypothesis Testing: Jogger Oxygen Uptake Example

A physician claims that joggers' maximal volume oxygen uptake is greater than the average of all adults. A sample of 15 joggers has a mean of 43.6 milliliters per kilogram (ml/kg) and a standard deviation of 6 ml/kg. If the average of all adults is 36.7 ml/kg, is there enough evidence to support the physician's claim at a = 0.05

### Hypothesis Testing of Mean Purchases

A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of \$5.29 with a standard deviation of \$3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was \$5.12 with a standard deviation of \$2.14. The means appear to be very close, bu

### Hypothesis Testing -To test the hypothesis that students who finish an exam first get better grades ... (Please see the attached file)

10.46 To test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of 19.6, while the last 24 papers handed in showed a mean score of 69.3 with a standard deviat

### Texas Study... (Please see the attached file.)

10.44 Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study, researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (average age 58). After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the inactive pill. (a) State t

### Statistics: Accident Rate

In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At alpha = .01, did the yellow fire trucks have a significantly low

### Econometrics

Problem: 5-Dec Alaska American America West British Continental 7.74% 7.67% -0.89% -2.52% 4.12% Delta JetBlue Northwest Southwest US Airways 4.45% 3.14% 4.84% 3.53% No Change Estimate the variance of the percent change in airline stock 6-Dec

### Statistics - Hypothesis Testing Evidence

A food processor specifies the mean weight of a product as 200g. A random sample of 20 has a mean of 195g and a standard deviation of 15g. Does this evidence suggest that the mean weight is too low?

### Statistics - Probability and Hypothesis Testing

1. The mean life of a computer disk drive is 2,000 hours. The standard deviation is 140 hours. Assuming the life-time of the drives to be normally distributed, find the probability of a disk drive lasting more than 1,800 hours. a. .4236 b. .9236 c. .8472 d. .5764 e. .2118 f. None of the above. 2. T