Essay on Math 533 Final Exm

a. The time (in years) it takes a sample of students to graduate college (Mean)

You work in marketing for a company that produces work boots. Quality control has sent you a memo detailing the length of time before the boots wear out under heavy use. They find that the boots wear out in an average of 208 days, but the exact amount of time varies, following a normal distribution with a standard

6. Based on questions 3, 4, and 5 is the mean or median a better estimate for the parameter of interest? Explain your reasoning.

Ryerson Automobile Insurance Company wants to estimate the mean time it takes for workers who are employed in downtown Toronto to get to work. A sample of 10 workers reveals the following number of minutes traveled.

Is this estimate centered about the parameter of interest (the parameter of interest is the answer for the mean in question 2)?

The performances of a group of interns are evaluated by their supervisors at the end of their internships.

5. Find the sample variance s2 for the following sample data. Round your answer to the nearest hundredth.

In order to estimate the percentage of defects in a recent manufacturing batch, a quality control manager at Intel selected every 8th chip that comes off the assembly line starting with the 3rd, until she obtains a sample of 140 chips.

Quality Associates, Inc. is a consulting firm that advises its clients about sampling and statistical procedures that can be used to control manufacturing processes. In one case, a client provided Quality Associates with a sample of 800 observations that were taken during a time when the client's process was operating satisfactorily. The sample standard deviation for these data was .21, hence, the population standard deviation was assumed to be .21. Quality Associates then suggested that random samples of size 30 be taken periodically to monitor the process on an ongoing basis. By analyzing the new samples, the client could quickly learn whether the process was operating satisfactorily. When the process was not operating

A company with factories located in New York and Michigan produce yarn, using two different types of machines; JC980 and VH80. Each factory uses only one machine type. The sample size is at 1 391 factories.

28. The Polo Development Firm is building a shopping center. It has informed renters that their rental spaces will be ready for occupancy in 19 months.  If the expected time until the shopping center is completed is estimated to be 14 months, with a standard deviation of 4 months, what is the probability that the renters will not be able to occupy in 19 months?

v. What are the limitations, if any, to the estimates of the profitability of the two customers? (Hint: Consider what improvements could be made to the accounting system to obtain more accurate costs)

d) Among all employees whose starting salary is below the median ($37,750), find a 95% confidence interval for the proportion who stay with D&Y for at least 3 years.

How many repair records should be sampled if the research firm wants the population mean number of miles driven until transmission failure to be estimated with the margin of error of 5000 miles? Use 95% confidence.

I have placed the results from our experiment in form of a table and will use the average results to form a graph. I have also prepared a graph to show the results throughout the exercise.