Resource: Statistical Techniques in Business &Economics
Prepare responses to the following exercises from the text:
Exercises 80, 82, and 87 (Ch. 3)

80. Creek Ratz is a very popular restaurant located along the coast of northern Florida. They serve a variety of steak and seafood dinners. During the summer beach season, they do not take reservations or accept “call ahead” seating. Management of the restaurant is concerned with the time a patron must wait before being seated for dinner. Listed below is the wait time, in minutes, for the 25 tables seated last Saturday night.

a. Explain why the times are a population.
b. Find the mean and median of the times.
c. Find the range and the standard deviation of the times.

Exercises 34, 36, and 38 (Ch. 5) p164

34. P(A1) = .20, P(A2) = .40, and P(A3) = .40. P(B1IA1) = .25. P(B1IA2) = .05, and P(B1lAe) = .10. Use Bayes’ theorem to determine P(A3 @ B1).

36. Dr. Stallter has been teaching basic statistics for many years. She knows that 80 percent of the students will complete the assigned problems. She has also determined that among those who do their assignments, 90 percent will pass the course. Among those students who do not do their homework, 60 percent will pass. Mike Fishbaugh took statistics last semester from Dr. Stallter and received a passing grade. What is the probability that he completed the assignments?

38. One-fourth of the residents of the Burning Ridge Estates leave their garage doors open when they are away from home. The local chief of police estimates that 5 percent of the garages with open doors will have something stolen, but only 1 percent of those closed will have something stolen. If a garage is robbed, what is the probability the doors were left open?

Exercises 45 and 62 (Ch. 6)
45. A Tamiami shearing machine is producing 10 percent defective pieces, which is abnormally high. The quality control...

...Individual Assignment: Types of Surveys
Question 5 on p. 270 of Business Research Methods.
Patricia Figueroa
November 17, 2009
Qnt561
Christopher Ajagu
In the following situations, decide whether you would use a personal interview, telephone survey, or self-administered questionnaire. Give your reasons.
a A survey of the residents of a new subdivision on why they happened to select that area in which to live. You also wish to secure some information about what they like and do not like about life in the subdivision.
For this group we can use a focus group which is used as a preliminary research technique to explore peoples ideas and attitudes. It is often used to test new approaches (such as products or advertising), and to discover customer concerns. A group of 6 to 20 people meet in a conference-room-like setting with a trained moderator. The room usually contains a one-way mirror for viewing, including audio and video capabilities. The moderator leads the group's discussion and keeps the focus on the areas you want to explore. Focus groups can be conducted within a couple of weeks and cost between two and three thousand dollars. Their disadvantage is that the sample is small and may not be representative of the population in general. For this survey I would recommend a self-administered survey since the people are in a central location that can be studied via paper or computerized instrument...

...Week 6 Team D Discussion – Regression Analysis
QNT/561
November 28, 2011
Jonathan Edelman
Week 6 Team D Discussion – Regression Analysis
The following paper summarizes the review and discussion process undertaken by Team D examining four articles that each detailed one or more applications of regression analysis.
Comparison Methods of Multiple Linear Regressions in Fish Landing
Multiple linear regression (MLR) is used to analyze the relationship between a single response variable (dependent variable) and two or more controlled variables (independent variables). The main objective of the paper, ‘Comparison Methods of Multiple Linear Regressions in Fish Landing’, written by Ghani, Intan, and Sabri (2011), is to make comparisons between independent variables and marine fish landing. Data is taken from Fisheries Annually Statistics of Department of Fisheries Malaysia focusing on the marine fish landing in Terengganu during the 40 year period of 1968 until 2007.
Many researchers have conducted research about fish leveraging MLR. In 2009, researchers Ahmad and Mamat conducted MLR research to identify the key factors correlated with a youth’s interest in becoming a fisherman. MLR revealed that the three factors most strongly correlated with respondents’ interest in a fishing career were training programs, profit, and marketing.
Ghani, Intan, and Sabri (2011) chose to leverage MLR for their research given the...

...Central Limit Theorem and Confidence Intervals Problem Sets
Tiffany Blount
QNT561
September 7, 2010
Michelle Barnet
University of Phoenix
Central Limit Theorem and Confidence Intervals Problem Sets
Chapter 8 Exercises:
21. What is sampling error? Could the value of the sampling error be zero? If it were zero, what would this mean?
* Sampling error is the difference between the statistic estimated from a sample and the true population statistic. It is not impossible for the sampling error to not be zero. If the sampling error is zero then the population is uniform. For example if I were evaluating the ethnicities of a populations and everyone is the population was Black then taking any sample would give me the true proportion of 100% Black.
22. List the reasons for sampling. Give an example of each reason for sampling.
* The population size is too large and costly for making the study feasible in reasonable period.
For example, if I want to know how watching the violent shows on television affects the behavior of children, it won’t be realistic to study each child in the population, so I would use sampling.
* Only estimation of particular section of population is required
For example, if I want to take an example of nation which is combined unit of states. I can choose the random samples of states which can be further divided into smaller units like cities. These cities can be clustered into smaller areas for...

...Week Four Team Paper
xxxxxxxxxxxxxx
QNT/561
August 1, 2012
xxxxxxxxx
Week 4 Team Paper
Best Buy is a company that has 40 years of history with a very accomplished sense of success. In 1966 Best Buy was a small electronics store in that originated in St. Paul Minnesota by Richard Schulze and an acquainted business partner. Considering that technology changes so rapidly, Best Buy has had to transform from just being the little electronics store down the way into a competitive, customer-driven, talent-powered company that emphasizes on pleasing the customers as it pertains to the life of technology. In 1993 Best Buy was recognized as the nation’s second largest electronics retailer and was recognized by Forbes in 2004 as the “Company of the Year.” However, in 2012 Best Buy had a huge layoff which resulted into 50 store closings. The competitors for Best buy include online stores like Amazon, Buy.com, Tiger direct and various others.
Purpose
Best Buy stores are located throughout the United States and every year additional employees are hired to help staff during the holiday season (known as seasonal staffing and typically runs during holiday season). Higher head count is inefficient and expensive. This poses an organizational dilemma; can sales data be used to identify the appropriate number of temporary employees that need to be hired during the holiday season? Considering the sheer amount of stores that...

...Individual Assignment:
Week 4
QNT561
November 1, 2010
Lee Chang
Question 5
In the following situations, decide whether you would use a personal interview, telephone survey, or self-administered questionnaire. Give your reasons.
a) A survey of the residents of a new subdivision on why they happened to select that area in which to live. You also wish to secure some information about what they like and do not like about life in the subdivision.
In this situation I would use a personal interview to acquire the desired information. Many subdivisions have an interview process before with the association to fit the required profile of the neighborhood and some of the information can be obtained at the initial interview. After some time passes a follow up interview can be conducted to acquire the rest of the information. In addition minimal staff is needed to conduct the surveys and get the information which means a lower cost. This will also lead to good cooperation from the new residents of the sub-division.
b.) A poll of students at Metro University on their preferences among three candidates who are running for president of the student government.
For this situation I would choose a personal interview. On many campuses these types of surveys are administered by a volunteer student group. The use of the groups means less overhead costs making the personal interviews favorable and able to endure for weeks before the vote. For the...

...
In this paperwork of QNT561 Final Exam you will find the answers on the next questions:
1. A difference between calculating the sample mean and the population mean is
2. Which of the following measures of central location is affected most by extreme values?
3. Which level of measurement is required for the median?
4. In which of the following distributions is the probability of a success usually small?
5. Which of the following is not a requirement of a probability distribution?
6. Which of the following is not a requirement of a binomial distribution?
7. A sample
8. The difference between the sample mean and the population mean is called the
9. Suppose a population consisted of 20 items. How many different sample of n = 3 are possible?
10. A point estimate is
11. We wish to develop a confidence interval for the population mean. The population follows the normal distribution, the standard deviation of the population is 3, and we have a sample of 10 observations. We decide to use the 90 percent level of confidence. The appropriate value of to represent the level of confidence is
12. A confidence interval
13. The Special Rule of Addition is used to combine
14. We use the General Rule of Multiplication to combine
15. An experiment is a
16. Which of the following statements is true regarding a sample?
17. Which of the following statements is true regarding a population?...

...the difference between the largest and the smallest values in the data set.
QNT561 – Week 1 Problem Set 3
- The largest value in the set of times is 67 and the smallest is 23.
- 67-23
= 44
d. Find the standard deviation of the times.
To do this, I first took the mean of the times (41 minutes) and subtracted it from each individual midpoint time. The next step was to square each difference and add all of them to get one total sum. Next, I took the total sum of squared differences and divided it by the number of times (25) minus 1. The final step was to take the square root of this total to get the standard deviation.
- 5292 (total of squared differences)
- 5292/25-1 (total of squared differences/number of times – 1)
- 220.5 (take the square root of this number)
= 14.85 minutes is the standard deviation
82. The following frequency distribution reports the electricity cost for a sample of 50 two-bedroom apartments in Albuquerque, New Mexico during the month of May last year.
|Electricity Cost |Frequency |
|$ 80 up to $100 |3 |
|100 up to 120 |8 |
|120 up to 140 |12 |
|140 up to 160 |16 |
|160 up to 180 |7 |
|180 up to 200 |4 |
| Total |50 |
QNT561 – Week 1 Problem...

...
Name
Assignment
QNT/561
Date
Descriptive Statistics
Sales (in USD)
The distribution is normally distributed.
Central Tendency:
Mean = 42.84 dollars.
Dispersion:
Standard deviation = 9.073 dollars.
Count:
100
Min/Max:
Min is $23.00; Max is $64.00
Confidence Interval (alpha = 0.05):
$41.06 to $44.62
The histogram is present in Appendix A; the descriptive statistics are present in Appendix B.
Age
The distribution is not normally distributed.
Central Tendency:
Median = 35 years
Dispersion:
Interquartile Range = 12 years / 2 = ± 6 years
Count:
100
Min/Max:
Min is 25 years; Max is 45 years
Confidence Interval:
The data is not normally distributed, therefore there is no confidence interval
The histogram is present in Appendix A; the descriptive statistics are present in Appendix B; the scatterplot relating age and sales is in Appendix C.
ID On Display
Thirty-four percent of the people sampled did not have their ID on display while sixty-six percent of people sampled had their ID on display. The bar chart is in Appendix E.
Descriptive Statistics Interpretation
Sales
One hundred people were randomly selected, and their sales were measured. Their sales were observed between $23.00 and $64.00. The average sales were $42.84, with a standard deviation of $9.07. Approximately half or more of the data values are above $42.84. There is enough evidence to say that the population sales amount lies between $41.06 and $44.62 with...