Question

1. Start a new worksheet and name it Z-scores. Use the STANDARDIZE function in Excel to calculate the z-scores for problems 2 and 4 on page 401 and problems 2 and 4 on page 412. Read Examples T.3 and T.4 on page 422 to see examples of how to use STANDARDIZE with means and proportions. Your output should look like the partial worksheet at right, except that cells C3, C4, C9, and C10 should be filled with the correct z-scores for each problem. (4 pts)

2. Start a new worksheet and name it Puppies. Then, complete the following: Suppose you are thinking about getting a puppy and want to know the amount of time people spend caring for their puppies. You survey 31 puppy owners and find that the mean amount of time they spend caring for their puppies is 108.0 minutes per day, with a standard deviation of 17.0 minutes. Construct and interpret a 98% confidence interval for the mean amount of time puppy owners spend on their puppies. Be sure to read page 500 and then use either Example T.7 or T.8 as a guide, whichever applies to this situation. Store your margin of error in cell A1. Then, write two (or more) complete sentences stating and interpreting your confidence interval. Write these in your worksheet in cell A4. For rounding, use the rounding rule on page 432.

Worth 4 points: 1 point for inputting data correctly, 1 point for getting the correct margin of error, and 2 points for correctly stating and interpreting the confidence interval.

3. Start a new worksheet and name it Chips. A random sample of 200 computer chips is obtained from a factory and 4% are found to be defective. Construct and interpret a 95% confidence interval for the proportion of all computer chips from the factory that are defective. Use Example T.9 on page 501 as a guide and format your answer like the example. (Note: Be sure that you are clear about what x, n, and p-hat are in this problem before you just enter numbers into Excel.) Write your sentences in cell A9. (The function in Excel 2007 is NORMSINV, but you will need to read about the NORMSINV function and think about what the first parameter will need to be to do this problem correctly.)

Worth 4 points: 1 point for inputting data correctly, 1 point for calculating the correct margin of error, and 2 points for correctly stating and interpreting the confidence interval.

Part 2

For problems 4-5, perform hypothesis tests for each of the following scenarios. You may use Excel, manual calculation, or a TI-83 or TI-84 calculator to compute your results. Submit your project to the Project 3 assignments folder on Brightspace by the due date. The easiest way to complete this project is to just take this Word document, fill in your answers, save it and submit to the assignments folder as Project3.docx. If you don’t have Word on your computer, you can print the pdf version of this document, write in your answers, and then scan it to a new pdf before submitting.

Grading for each problem is as follows:

Hypotheses: 1.5 points = To receive full points, hypotheses (both H0 and Ha) must be stated correctly, either in words or in symbols. Examples: “µ ≥ 35” or “Population mean is greater than or equal to 35”.

Test stat and value: 1 point = Identify the correct test statistic and its value (Example: t = 2.215)

P-value (or Critical Value): 1 point = Correct p-value (or Critical value on #4) of test is given.

Conclusion: 1.5 points = State how you decided and whether you reject or fail to reject null hypothesis. Then, include a full sentence description of what this means in this particular problem. (Example: “Since the p-value > the 0.05 significance level, fail to reject H0. There is not enough evidence to support the claim that listening to music while studying increases your chances of getting an A.”)

4. A children’s clothing company sells hand-smocked dresses for girls. The length of one particular size of dress is designed to be 26 inches. The company regularly tests the lengths of the garments to ensure quality control, and if the mean length is found to be significantly longer or shorter than 26 inches, the machines must be adjusted. The most recent simple random sample of 28 dresses had a mean length of 26.30 inches with a standard deviation of 0.77 inches. Perform a hypothesis test at the 0.01 level of significance to determine if the mean dress length has changed.

Hypotheses:

Test statistic and value:                                                                  P-value or Critical value:

Conclusion:

5. CNN/Money reports that the mean cost of a speeding ticket, including court fees, was $150.00 in 2002. A local police department claims that this amount has increased. To test their claim, they collected data from a simple random sample of 160 drivers were fined for speeding in the year 2002 and found that they paid a mean of $154.00 per ticket. Assuming that the population standard deviation is $17.54, is there sufficient evidence to support the police department’s claim at the 0.01 level of significance?

Hypotheses:

Test Statistic and value:                                                                     P-value:

Conclusion:

Answer 1

4)

Please post one question at a time

Also Q1-3 require data from book.