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# Hypothesis Testing

### Last year the records of Dairy Land Inc., a convenience store chain, showed the mean amount spent by a customer was \$30. A sample of 40 transactions this month revealed the mean amount spent was \$33 with a standard deviation of \$12. At the 0.05 significance level, can we conclude that the mean amount spent has increased? What is the p-value? Follow the five-step hypothesis testing procedure.

Last year the records of Dairy Land Inc., a convenience store chain, showed the mean amount spent by a customer was \$30. A sample of 40 transactions this month revealed the mean amount spent was \$33 with a standard deviation of \$12. At the 0.05 significance level, can we conclude that the mean amount spent has increased? What

### 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 &#945; = .01, did the yellow fire trucks ...

10:30: 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 &#945; = .01, did the yellow fire trucks have a signi

### Null hypothesis - A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, ...

A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6, 3.8, 4.0, and 3.9. What is the decision rule at the 0.01 level of significanc

### Hypothesis testing to compare two populations

11.The company believes that it averages about the same weight per bag in each of two production lines. To test this idea, they will perform a hypothesis test to compare the two lines at the alpha level of 0.05. State the null and alternative hypotheses: 12.If the test calculates a sample Z of 1.69, what is the corresponding

### Hypothesis testing - 1.A company is filling bags of rock salt to a level of 50 pounds. It believes that all bags are filled correctly, but would like to use a hypothesis test with an alpha of 0.05 to check this belief. The company will be using samples of 100 bags from each run to do the test. State the null and alternative hypotheses: ...

1.A company is filling bags of rock salt to a level of 50 pounds. It believes that all bags are filled correctly, but would like to use a hypothesis test with an alpha of 0.05 to check this belief. The company will be using samples of 100 bags from each run to do the test. State the null and alternative hypotheses: Is this a

### Are quantitative techniques (such as multiple regression analysis) of little value because they are always subject to error?

It is sometimes argued that quantitative techniques such as multiple regression analysis, are of little value because they are always subject to error. Is this a valid argument? Carefully Explain.

### Hypothesis Testing Question

The manufacturer of batteries for aircraft emergency vehicles claims that lifetime of the 1500 batteries that have been manufactured is normally distributed with a mean of at least 30 months and a standard deviation of 3 months. An aircraft manufacturer checks out 25 batteries that they purchased and discovers a sample mean of

### Test the claim that the shirt sleeves are at least 33 inches.

The buyer of shirts for a department store wants to test whether shirts with sleeve labels of "33 inches" are at least that specification on average. A random sample of n = 100 from 10,000 incoming shirts is to be taken. The sample shows a mean length of 34 inches, with a standard deviation of 2 inches. Find the P value.

### Hypothesis Testing for Police Road Blocks

Please see the attached file. Consider the use of Police road blocks to detect people that are driving intoxicated. a. What are the null and alternative hypothesis? b. What are the type I and type II errors in this case? c. Which type of error is more costly? d. Based on your answer to part (c), what value of

### Formulating a Research Question and Hypothesis Statement

Develop one research question and formulate a hypothesis which can be tested with linear regression analysis. Formulate a hypothesis statement regarding your research issue.

### Converting z intervals to x intervals

Convert each z interval to x interval a) -2.17<z b) z<1.28 c) -1.99<z<1.44 d) If the weight is 14 would it be a small animal? e) If it is large would you say z value for the weight of the fawn will be close to 0, -2, or 3 explain. What is given is the mean=27.2 kilograms and standard deviation=4.3 kilograms. I at

### Formulating Hypothesis Statements for Real Estate Data

Need help formulating a hypothesis statement regarding the real estate data stats enclosed.

### Statistics - Null Hypothesis..

A man is on trial accused of murder in the first degree. The prosecutor presents evidence that he hopes will convince the jury to reject the hypothesis that the man is innocent. This situation can be modeled as a significance test with the following hypotheses: Ho: The defendant is innocent H1: The defendant is not inn

### Statistics: Why can the null hypothesis not be proved?

Suppose that you perform a significance test regarding a population mean, and that the evidence does not warrant rejection of the null hypothesis. When formulating the conclusion to the test, why is the phrase "fail to reject the null hypothesis" more accurate than the phrase "accept the null hypothesis"? Why can the null hypoth

### Hypothesis Testing the Effectiveness of Aspirin

3. A physician's health study of the effectiveness of aspirin in the reduction of heart attacks was begun in 1982 and completed in 1987. Of 11,037 male medical doctors in the United States who took one 325mg buffered aspirin tablet every other day, 104 suffered heart attacks during the five-year period of the study. Of 11,034

### One Tailed Hypothesis test

To test the hypothesis that students who finish an exam first get better grades, a professor kept track of the order in which paper were handed in. the first 25 paper showed a mean score of 77.1 with a standard deviation of 19.6. the last 24 paper turned in showed a mean score of 69.3 with a standard deviation of 24.9. Is this a

### Hypothesis Testing for Incidence of Heart Attacks

Does lovastatin reduce the risk of heart attack? Researchers gave lovastatin to 2,325 people and an placebo to 2,081 people. the average age of both groups in 58 years. After 5 years, 57 of the lavastatin group had suffered a heart attack, compared to 97 from the placebo group. At a=.01, can we conclude that the lovastatin users

### F Distribution Test Example

What do we use the F Distribution to test? Provide an example from your place of employment or circle of influence of an instance when you could use the F Distribution.

### Hypothesis Testing using Statistical Software Output

Directions: You may include the statistical software output, but you must also include a well-written explanation of the findings. Be sure to answer the question asked in each problem, and explain why, with reference to your output. If you calculate the answers manually, be sure to show your work. I would prefer a Word document

### 13 Statistics Questions

Please see attachment. Thank you. [1.] A recent article in the Topeka Times reported that 40% of all farms in Kansas will have financial problems this year. A recent survey of 200 farms revealed that 66 of them had financial problems. At the &#945; = 0.01 significance level can we conclude that a smaller proportion of far

### Hypothesis Testing Using Alpha and Significance Levels

1) A trucking firm suspects that the mean lifetime of a certain tire uses is less than 35,000miles. To check the claim the firm randomly selects and tests 54 of these tires and gets a mean life time of 34,570 with a standard deviation of 1200 miles. At a alpha = 0.05 test the trucking firms claims. 2) A local brewery distribu

### Clarification of Regression

In the following regression (see attached data), X=total assets (\$ billions), Y=total revenue (\$ billions), and n=64 large banks. a. Write the fitted regression equation. b. State the degrees of freedom for a two-tailed test for zero slope, and use Appendix D (see attached data) to find the critical value at a=.05.

### Inflation Rate: Regression

An attempt was made to evaluate the inflation rate as a predictor of the spot rate in the German treasury bill market. For a sample of 29 quarterly observations the estimated linear regression Y hat = 0.0027 + 0.791X was obtained, where Y = the actual change in the spot rate X = Change in the spot rate predicted by

### P-value and Hypothesis Testing

9.54 Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard

### Hypothesis Testing on Three Scenarios

1. An aircraft manufacturer is attempting to determine if the average leg length of the adult male has changed from 44". A sample of 81 men was selected randomly and the average length was found to be 45.5", with a standard deviation of 5.5". Test the null hypothesis that the average leg length of the adult male is 44", at a = 0

### Sample Test - Suppose you heard a rumor that there was a difference in the salaries for men and women at your company. You decide to take a sample of employees and test the claim. The file represents ...

Suppose you heard a rumor that there was a difference in the salaries for men and women at your company. You decide to take a sample of employees and test the claim. The file represents a random sample of 100 employees. Use a 0.05 significance level, test whether there is a difference in the mean salary for men versus women. No

### The retailing manager of a supermarket chain wants to determine whether product location has any effect on the sale of pet toys. Three different aisle locations are considered: front, middle, and rear. A random sample of 18 stores is selected, with 6 stores randomly assigned to each aisle location. [See the attached Question file.]

The retailing manager of a supermarket chain wants to determine whether product location has any effect on the sale of pet toys. Three different aisle locations are considered: front, middle, and rear. A random sample of 18 stores is selected, with 6 stores randomly assigned to each aisle location. The size of the display are

### Sample Test - A newspaper article discussed the opening of a Whole Foods Market in the Time-Warner building in New York City. The following data compared the prices of some kitchen staples ...

A newspaper article discussed the opening of a Whole Foods Market in the Time-Warner building in New York City. The following data compared the prices of some kitchen staples at the new Whole Foods Market and at the Fairway supermarket located about 15 blocks from the Time-Warner building: Half-gallon milk Whole Foods Pri

### Hypothesis Test for the Mean: Did the dietitian see a difference in results between the two treatments?

A dietitian investigated whether apples washed in hot water or in cold water turned brown at different rates when exposed to air. She took 13 random apples and cut each in half. She washed one half of each apple in hot water and the other half in cold water, and then put both halves out in a tray. Her results (in hours until tu

### Statistics of tennis

A health club has six tennis courts. The owner hypothesizes that his patrons have no preference for a particular court. He observes how many people play on each court on a particular day. Compute the expected value for the data shown below. Court.......Number of Players 1..........................9 2.....................