# TUTORIALS

QNT/275 Statistics for Decision Making

QNT/275 Week 1

Includes Option #1

Includes Option #2
Write a 300-word summary that addresses the following criteria:
• Define statistics.
• Identify different types and levels of statistics.
• Describe the role of statistics in business decision-making.
• Provide at least two examples or problem situations in which statistics was used or could

be used.
Format your summary consistent with APA guidelines.
Click the Assignment Files tab to submit your assignment.

Note: Discussion Questions may be different, depending on which Instructor you get.

Learning Activity: The Role of Statistics in Business Decision-Making video

Watch the "The Role of Statistics in Business Decision-Making" video.
Consider the following as you watch:
• Describe probability theory.
• Explain how sampling theory relates to probability theory.
• Differentiate between a population and a sample.
• Explain, based on the video, why statistics is important in decision-making.

# COMING SOON!

QNT/275 Week 2

Prepare a paper examining a business problem confronting your organization or an organization you know of that you feel could be addressed through the application of the business research process. Describe the problem.
Then present the research purpose and one research question addressing an aspect of this problem. The question must contain the variable you will measure. Discuss the measured variable. Use the business research problem sample I2 as a guide. This paper should be
between 300-600 words. Post to the individual assignment forum. Title the document file "Business Statistics Research Problem I2".

Note: Discussion Questions may be different, depending on which Instructor you get.

Learning Activity: Obtaining a Suitable Sample
Watch the "Obtaining a Suitable Sample" video.
Consider the following as you watch:
• Discuss the difference between convenience and random sampling.
• Explain how you can obtain a sample size representative of a population.
• Provide three examples.
• Explain why a sample is used in place of the population.

Learning Activity: Measuring Central Tendency and Variability

Watch the "Measuring Central Tendency and Variability" video.
Consider the following as you watch:
• Define the three standard measurements of the central tendency and provide example of each.
• Explain when you might want to use a median number.
• Provide an example.
• Define a standard deviation and what a standard deviation shows, provide an example.

Learning Activity: Mean, Median, and Variability

Watch the "Measuring Central Tendency and Variability" video.
Consider the following as you watch:
• Define the three standard measurements of the central tendency and provide example of each.
• Explain when you might want to use a median number.
• Provide an example.
• Define a standard deviation and what a standard deviation shows, provide an example.

Learning Activity: Mean, Median, and Mode

Watch the "Statistics Intro: Mean, Median, and Mode" video.
Consider the following as you watch:
• Explain how mean is calculated.
• Explain how a median is calculated with an even number list.
• Define an array.
• Provide an example.
• Define a mode.
• Identify if you can have more than one modal number in a set of data.

Learning Activity: Finding the Range and Mid-Range

Watch the "Finding the Range and Mid-Range" video.
Consider the following as you watch:
• Define a range and provide two examples.
• Calculate a mid-range and provide two examples

**********  BONUS FILES INCLUDED **********

Collaborative Discussion: Descriptive Statistics
Read Case Study 3.3 in Ch. 3 of Essentials of Business Statistics found on page 98.
Click the Fort Myers Sales Data Set link.
Calculate descriptive statistics:the mean, median, mode, and standard deviation in the two sample periods (January and July).
Discuss one of the following:
• Identify what changes occurred in the Fort Myers housing market during the 6-month period.
• Explain what conclusions you can draw from the data.
• Identify what additional data you might want to understand the housing market better.
• Explain what role descriptive statistics play in understanding the housing market.

Individual: Week 2 Quiz

1. ​In order to summarize qualitative data, a useful tool is a __________.
2. ​The accompanying chart shows the numbers of books written by each author in a collection of cookbooks. What type of chart is this?
3. ​A recent survey of 200 small firms (annual revenue less than \$10 million) asked whether an increase in the minimum wage would cause the firm to decrease capital spending. Possible responses to the survey question were: "Yes," "No," or "Don't Know." These data are best classified as ____________.
4. ​ABC Plumbing wants to understand its customers’ perceptions of the quality of the company’s plumbing service calls. They plan to survey a sample of its customer base. What will ABC need to do to ensure that their data is valid and reliable?
5. A stem-and-leaf diagram is constructed by separating each value of a data set into two parts. What are these parts?
6. A population consists of _________________.
7. ​Which of the following variables is qualitative?
8. ​Which of the following represents a population and a sample from that population?
9. Which of the following variables is quantitative?​

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QNT/275 Week 3

Individual Assignment: Descriptive Statistics

Identify a research problem different from the previous research problems that uses two different sets of the same type of data. You may use any business subject. Some examples: Sales from two different months or years. GPA's of men and women. Number of two different shelf items sold (Coke & Pepsi) by month over a year. Home sales prices in different suburbs, cities, counties or states. You wish to determine if there is a significant difference between the means of the data sets.

Select data that have absolute zero measurements (Ratio data). You may use recorded data or made up data. The n sample size should be at least 10 in each set, but not more than 29.

Prepare a paper describing the research problem, research purpose and one research
question.

Define the variable.

Discuss the type of data and determine
the level of measurement.

List the data. List alpha, the null and alternative hypothesis, and give a brief back ground. Using either Megastats or Analysis ToolPak do descriptive statistics on the data and
do data analysis describing the data. Do runs plot graphs.

Interpret the Goodness of Fit (GOF) p-value to decide if the data is parametric
(normal) or nonparametric.

Conclude. Use the sample I3 Descriptive Statistics as a guide.

This paper should be between 700-1000 words.
Post as an Individual Assignment. Title the document file "Descriptive Statistics I3".

**********  BONUS FILES INCLUDED  **********

Collaborative Discussion: Probability
Resource: Case Study 5.2 in Chapter 5 of Essentials of Business Statistics
Calculate the requested probabilities for items 1-3.
Discuss your findings for the probabilities.
• Identify the smoking trend from 1997-2007.
• Explain whether this is a discrete, continuous, or conditional probability.
• Recommend steps related to smoking behavior based on this trend.

Week 3 Quiz

1. For any normally distributed random variable with mean μ and standard deviation σ, the percent of the observations that fall between   and    is closest to _______. ​
2. 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 deviation of 14 days. For an upcoming ad campaign, you need to know the percent of the pairs that last longer than six months-that is, 180 days. Use the empirical rule to approximate this percent.​
3. What is probability?
4. ​Which of the following is correct?
5. ​A continuous random variable has the uniform distribution on the interval [ab] if its probability density functionf(x) ___________.
6. ​The probability that a normal random variable is less than its mean is ____.
7. ​Which of the following can be represented by a continuous random variable?
8. ​What does it mean when we say that the tails of the normal curve are asymptotic to the x axis?
9. ​Which of the following can be represented by a discrete random variable?
10. Mutually exclusive and collectively exhaustive events _______________.​

# QNT/275 Week 4

Individual Assignment: t-test

Identify a research problem different from the previous research problems that uses two different sets of the same type of data. You may use any business subject.
Some examples: Sales from two different months or years. GPA's of men and women. Number of two different shelf items sold (Coke& Pepsi) by month over a year. Home sales prices in different suburbs, cities, counties or states. You wish to determine if there is a significant
difference between the means of the data sets. Select data that have absolute zero measurements (Ratio data). You may use recorded data or made up data. The n sample size should be at least 10 in each set, but not more than 29. Prepare a paper with a table of contents.
Describe the research problem, research purpose and one research
question. Define the variable. Discuss the type of data and determine
the level of measurement. List the data. List alpha, the null and
alternative hypothesis, and give a brief back ground. Using either
Megastats or Analysis ToolPak do descriptive statistics on the data and
do data analysis describing the data. Do runs plot graphs. Interpret the
Goodness of Fit (GOF) p-value to decide if the data is parametric
(normal) or nonparametric. t-test: Open Excel, log in both data sets. Go
to Add Ins, or Analysis ToolPak, Hypothesis Tests, Compare Two
Independent Groups, (Assuming Equal Variances) left mouse click
highlight Group 1 then Group 2, OK. Conclude. Use the I4 sample as a
guide. This paper should be between 900-1200 words. Post as an
Individual assignment. Title the document file "t-test I4".

Note: Discussion Questions may be different, depending on which Instructor you get.

Learning Activity: Correlation and Causality

Watch the "Correlation and Causality" video.

• Define a correlation and provide an example
• Define causality?
• Explain if correlation causes causality.
• Provide evidence with an example.

Learning Activity: Using Time Series to Analyze Business Trends
Watch the "Using Time Series to Analyze Business Trends" video.
• Identify the four components of time series.
• Provide an example of each component and how it might be used in business

Explain if this data becomes obsolete over time.

Career Connection Discussion: Forecasting
Discuss the following:
• Explain what you have learned throughout this course with probability and how you think that will affect your forecasting decisions in your current or future company.
• Predict how you will use probability in your current or future company?

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Collaborative Discussion: Linear Regression
Resource: Case Study 12.1 in Chapter 12 of Essentials of Business Statistics.
Click the Sushi Restaurant Data Set link.
Calculate the linear regression in item 1 of the case study.
Discuss the following:
• Explain if simple regression or multiple regression is more appropriate for making predictions in this case.
• Predict what will happen to sales based on unemployment rate and the level of advertising

Week 4 Quiz

1. Which of the following violates the assumptions of regression analysis?
2. ​Consider the following simple linear regression model:   The response variable is:
3. ​Serial correlation is typically observed in:
4. ​The standard error of the estimate measures:
5. What is the name of the variable that's used to predict another variable?​
6. Which of the following variables is not qualitative?​
7. ​Another name for an explanatory variable is the ___.
8. Consider the following simple linear regression model:   β0 and β1 are:​
9. For a given set of explanatory variables, in general:
10. ​In a simple linear regression model, if the plots on a scatter diagram lie on a straight line, what is the standard error of the estimate?

QNT/275 - Week 5

CLO Business Decision Making Project, Part 3
Option#1: Bank of America Presentation

Option#2: Staples, Inc. Presentation

Option#3: Harris Bank Presentation
Prepare an 11- to 15-slide Microsoft PowerPoint presentation for the senior management team based on the business problem or opportunity you described in Weeks 3-4.
Include on the slides what you'd want the audience to see (include appropriate visual aids/layout) and include in the Speaker's Notes section what you'd say as you present each slide. If any source material
is quoted or paraphrased in the presentation, use APA citations and references.
Draw on material you developed in the Weeks 3-4 assignments.
Include the following in your presentation:
• Introduction slide
• Agenda slide
• Describe the organization, with a brief description
• Explain the business problem or opportunity
• Analyze why the business problem is important
• Identify what variable would be best to measure for this problem. Explain why.
• Apply data analysis techniques to this problem (tell which techniques should be used: descriptive stats, inferential stats, probability, linear regression, time series). Explain why.
• Apply a possible solution to the problem/opportunity, with rationale.
• Evaluate how data could be used to measure the implementation of such a solution.
• Conclusion
• References slide (if any source material is quoted or paraphrased throughout the presentation)
Format your assignment consistent with APA guidelines.

Week 5 Final Exam

QNT 275 Final Exam

**The questions will not be in this exact order**

1. What is the name of the variable that's used to predict another variable?
2. Professors at a local university earn an average salary of \$80,000 with a standard deviation of \$6,000. The salary distribution is approximately bell-shaped. What can be said about the percentage of salaries that are at least \$74,000?
3. What type of relationship is indicated in the scatterplot?
4. The study of statistics can be defined as:
5. In the accompanying stem-and-leaf diagram, the values in the stem and leaf portions represent 10s and 1s digits, respectively. The stem-and-leaf diagram shows that the distribution is __________.
6. ​​ Which of the following is most influenced by outliers?
7. Serial correlation is typically observed in:
8. In the sample regression equation   what is   ?
9. Bias can occur in sampling. Bias refers to ______________.
10. The manager of a retail shoe store has applied statistics to analyze sales, purchasing, and  data and reached the conclusion that the store could reduce costs by reducing inventory of very small and very large sizes, and substituting an online ordering service to drop-ship rare sizes directly from suppliers. How should the manager communicate those results to the store owner?
11. Which of the following can be represented by a continuous random variable?
12. Consider a population with data values of 12, 8, 28, 22, 12, 30, 14.The median is:
13. The salaries of teachers in a particular school district are normally distributed with a mean of \$50,000 and a standard deviation of \$2,500. Due to budget limitations, it has been decided that the teachers who are in the top 2.5% of the salaries would not get a raise. What is the salary level that divides the teachers into one group that gets a raise and one that doesn't?
14. The two branches of the study of statistics are generally referred to as ___________.
15. The estimation of which of the following requires sampling?
16. Which of the following meets the requirements of a stratified random sample?
17. A Manager of a fast food restaurant wants to ensure that staff are scheduled with the sufficient hours required to meet customer demands without overspending on labor costs. The manager has daily guest counts, sales data, and staff hours for the prior year. What should the manager do next in order to reach conclusions about scheduling restaurant staff?
18. A-Plus Dry Cleaners wants to understand its customers’ perceptions of the quality of the company’s customer service. They plan to survey a sample of its customer base. What will A-Plus need to do to ensure that their data is valid and reliable?
19. Which scales of data measurement are associated with quantitative data?
20. The owner of a company has recently decided to raise the salary of one employee, who was already making the highest salary, by 20%. Which of the following is (are) expected to be affected by this raise?
21. Which of the following violates the assumptions of regression analysis?
22. A hedge fund returns on average 26% per year with a standard deviation of 12%. Using the empirical rule, approximate the probability the fund returns over 50% next year.
23. Mutually exclusive events ______________.
24. What is (are) the most widely used measure(s) of dispersion?
25. Frequency distributions may be used to describe which of the following types of data?
26. A company wants to estimate the mean price of oil over the past 10 years. What kind of data does the company need?
27. Horizontal bar charts are constructed by placing:
28. Which of the following can be represented by a discrete random variable?
29. Which of the following is a quantitative variable?