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Hypothesis Testing

Test a manufacturer's claim that defective machines

A PC manufacturer claims that no more than 2% of their machines are defective. In a random sample fo 100 machines, it is found that 5 percent are defective. The manufacturer claims this is a fluke of the sample. At a 0.01 level of significance, test the manufacturer's claim and explain your answer. Test and CI for One Propor

Statistics regression anaylsis, Ho and null hypothesis

How do I determine sleep affect on GPA or is something else affecting grades as much, using statistics? Background There have been various studies that say students' grades are affected by poor diet, high amounts of stress, lack of sleep, and excessive alcohol use. Perhaps one of the most important factors out of those ment

Statistics of SPSS 2004GSS.sav data file

Crosstabulation: Examine variables in the "2004GSS.sav" data file. Choose one from the following three variables to be the dependent variable in the hypotheses you will establish. a. Grass b. Fear c. Gunlaw Choose another variable from the data

Statistical Tests: Hypotheses, Critical Region, and P-Value

Let p equal the proportion of drivers who use a seat belt in a country that does not have a mandatory seat belt law. It was claimed that p = 0.14. An advertising campaign was conducted to increase this proportion. Two months after the campaign, y = 104 out of a random sample of n = 590 drivers were wearing their seat belts. Was

Vehicle Type Vary by Mall Location

Exercise 15.22 A student team examined parked cars in four different suburban shopping malls. One hundred vehicles were examined in each location. Research Question: At a = .05, does vehicle type vary by mall location? Vehicle Type Somerset Oakland Great Lakes Jamestown Row Total Car

Hypothesis Testing

1. What is the five step process for hypothesis testing? Why or why not? What is the null hypothesis? Why is it important? What are its implications? Explain. You may use examples to show your understanding. 2. Why is it said that hypothesis testing involves a double negative logic? Explain why you think that this logic is i

Modification Sample Means for LSD Test

10. Three Radar modifications were tested for detection range improvement using five trials each. The following single factor ANOVA Table presents the results: (See attachment for table) The modification (Mod) sample means are: Mod A = 31.4, Mod B = 28.6,Mod C = 23.8 Using the Fisher LSD test, determine if any of the

Accepting the null hypothesis or failing to reject it

Consider the seven steps of hypothesis testing. The final step in the hypothesis-testing process involves deciding whether to reject the null hypothesis. Assuming the null hypothesis is not rejected, what is the difference between accepting the null hypothesis and failing to reject it? Explain your reasoning.

Statistics Population Defective Parts

1. If 10% of a population of parts is defective, what is the probability of randomly selecting 80 parts and finding that 12 or more parts are defective? 2. A survey was taken of U.S. companies that do business with firms in India. One of the questions on the survey was: Approximately how many years has your company been tra

Hypothesis Testing for Teaching Style and Gender

Please see attached file for proper format and formulas. All work has to be shown. If using SPSS a copy of your output and data file has to be present. Please use formulas. Below is the data that has to be used to answer all of the questions. The participants were 30 statistics students that were randomly selected to parti

Hypothesis Testing of Variance

A finance professor claims that there is much more variability in the final exam scores of students taking the introductory finance course as a requirement than for students taking the course as part of a major in finance. Random samples of 16 non-finance majors (group 1) and 10 finance majors (group 2) are taken from the profes

Hypothesis Testing: Animal Bone & Rock Examples

1. Four animal bone samples were discovered in the ditch terminals. These bones bore signs of attempts at artificial preservation and might have been in use for a substantial period of time before being placed at Stonehenge. When dated, these bones had a mean age of 3187.5 BC and standard deviation of 67.4 years. Assume that the

Hypothesis Test

Stonehenge's main ditch was dug in a series of segments. Excavations at the base of the ditch uncovered a number of antlers which bore signs of heavy use. These antlers could have been used by the builders as picks or rakes. The fact that no primary silt was discovered beneath the antlers suggests that they were buried in the di

Rejection Region

How is the rejection region defined and how is that related to the z-score and the p value? When do you reject or fail to reject the null hypothesis? Why do you think statisticians are asked to complete hypothesis testing? Can you think of examples in courts, in medicine, or in your area?


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


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 deviation of


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 the app


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 Ã?± = .01, did the yellow fire trucks have a significantly low

Test null hypothesis

The spotlight effect refers to overestimating the extent to which others notice your appearance or behavior, especially when you commit a social faux pas. Effectively, you feel as if you are suddenly standing in a spotlight with everyone looking. In one demonstration of this phenomenon, Gilovich, Medvec, and Savitsky (2000) aske

Hypothesis Testing: One population

4. The US department of education reports that 46% of full-time college students are employed while attending college. A recent survey of 600 full-time students at CCP found that 305 were employed. At a 5% level of significance, test to see if there is sufficient evidence that the proportion of full-time students who are employ

Z test and hypothesis testing

Please help with the following problem. The mean waiting time for the drive-through window of a fast-food franchise is believed to be 3.7 minutes. A manager wants to check the time at her particular restaurant. A sample of 75 customers is selected and the sample mean waiting time is 3.57 minutes with a sample standard deviat

Statistical testing using a level of significance

System data for a job shop revealed that the average time spent by a job in the shop was approximately n = 5 working days. A random sample of size five is taken with time spent in the shop, 3.7, 4.6, 3.9, 4.1, and 3.8. Is the output consistent with system behavior? (Why?). Construct a statistical test using a level of signific

Comparing two population variances: Example question

If a random sample of 5 observations from one population results in a standard deviation of 12 and the other random sample of 7 observations results in a standard deviation of 7, with a significance level of .01 is there a variance in the first population. Looking to see how to layout work in this situation. And how to compare

Statistics of SPSS file

Perform appropriate statistics for each of the following variables in the data file "" 1) age, 2) gender, 3) race, and 4) class. The choice of statistics should be either percentage with bar chart (for categorical/discrete variables), or the mean and standard deviation for continuous/ratio variables. For categorical v

Consider a chemical company that wishes to determine whether a new catalyst

Consider a chemical company that wishes to determine whether a new catalyst, catalyst XA-100, changes the mean hourly yield of its chemical process from the historical process mean of 750 pounds per hour. When five trial runs are made using the new catalyst, the following yields (in pounds per hour) are recorded: 801, 814, 7

The Crown Bottling Company 2

The Crown Bottling Company has just installed a new bottling process that will fill 16-ounce bottles of the popular Crown Classic Cola soft drink. Both overfilling and underfilling bottles are undesirable: Underfilling leads to customer complaints and overfilling costs the company considerable money. In order to verify that the