In an attempt to increase business on Monday nights, a restaurant offers a free dessert with every dinner order.  Before the offer, the mean number of dinner customers on Monday was 150.  The numbers of diners on a random sample of 12 days while the offer was in effect are selected.  Can you conclude that the mean number of diners increased while the free dessert offer was in effect?

What is (are) the parameter(s) of interest?

Construct a normal probability plot and a boxplot to visualize the distribution of your sample data.  Copy and paste these graphs into your assignment.  Below the graphs, answer the following questions.

Are there any major deviations from normality?  

Are there any outliers present?  

Is it appropriate to conduct statistical inference procedures, why or why not?

If the answer to part iii is no, do not complete the rest of #3.

At the 0.05 significance level, can you conclude that the mean number of diners increased from 150 while the free dessert offer was in effect?

State the null and alternative hypotheses.

State the significance level for this problem.

Calculate the test statistic.  

Calculate the P-value and include the probability notation statement.

State whether you reject or do not reject the null hypothesis.

State your conclusion in context of the problem (i.e. interpret your results).

Construct a 99% confidence interval for the above data.  Interpret the confidence interval.

 According to a report of the Nielsen Company, 65% of Internet searches used Google as the search engine.  Assume that a sample of 13 searches is studied.  Let the random variable  be the number of searches where Google was used.  

What is the name of the probability distribution of X?  Write out the setting (i.e. write out the four requirements of a particular setting that you learned in class).

Produce a table that lists the possible values of the random variable and the corresponding probabilities of each value’s occurrence.

What is the mean of this distribution?  Show work using the formula.

What is the standard deviation of this distribution?  Show work using the formula.

Calculate the probability that of the 13 searches analyzed, at least 8 of those searches used Google.  Display a Minitab Graph with the correct portion shaded as the answer to this question.  Then, verify your answer with using the table you displayed in part (b).

According to the U.S. Department of Agriculture, 58.8% of males between 20 and 39 years old consume the minimum daily requirement of calcium.  After an aggressive “Got milk” advertising campaign, the USDA conducted a survey of 55 randomly selected males between the ages of 20 and 39 and finds that 36 of them consume the recommended daily allowance of calcium. 

If we conduct statistical inference above, what is (are) the parameter(s) of interest?

Construct a 96% confidence interval for the above data.  Interpret the confidence interval as we learned in class.  Show your work using the formulas.

Construct a 96% confidence interval for the above data using the Plus Four Estimate.  Interpret the confidence interval as we learned in class.  Show your work using the formulas.

At the 0.05 significance level, is there evidence to conclude that the percentage of males between the ages of 20 and 39 who consume the recommended daily allowance of calcium has increased?

State the null and alternative hypotheses.

State the significance level for this problem.

Check the conditions that allow you to use the test statistic, and, if appropriate, calculate the test statistic.

Calculate the P-value and include the probability notation statement.

State whether you reject or do not reject the null hypothesis.

State your conclusion in context of the problem (i.e. interpret your results).

Questions 1 to 20: Select the best answer to each question. Note that a question and its answers may be split across a page

break, so be sure that you have seen the entire question and all the answers before choosing an answer.

1. With a USB keyboard, you’ll be able to enter commands as soon as

A. the power switch is turned to ON.

B. the Windows OS loads the USB driver.

C. the Windows logo screen displays on the monitor.

D. a single beep tone is heard.

2. The best place to store a heavy object such as a display monitor is on

A. a shelf about six inches above the floor.

B. a shelf about five feet above the floor.

C. a shelf about waist height.

D. the floor.

3. You turn on your PC and it begins to power up but fails to reach the point where your operating system

screen is displayed. Which of the following tools might help you to troubleshoot the problem?

A. Multimeter

B. Diagnostic software

C. RS-232 minitester

D. POST diagnostic card

4. Complete this sentence with the most accurate statement:

“Magnetized tools in PC repair

A. help keep your toolbox organized.”

B. facilitate the process of starting screws and fasteners.”

C. make it easier to retrieve small parts that fall into the body of the computer.”

D. should never be used.”

5. You can reboot a PC from a floppy disk drive using

A. a virtual RAM drive.

B. a specially formatted Windows Start Up diskette.

C. any hard shell diskette with a sliding cover.

D. a blank IBM high density diskette.

6. To make a warranty claim on a defective PC, which of the following pieces of information is not

required?

A. Model

B. Original invoice

C. Sales person’s ID number

D. Serial number

7. You’ve just completed setting up your system and turned the power on. As the system begins to boot

up, it suddenly stops and displays a message indicating that it can’t detect a component. What should you

do next?

A. Check that all cables between the system unit and components are securely attached.

B. Call an electrician.

C. Look inside the system unit for loose or broken wires.

D. Ship the system back to the manufacturer with a written description of the problem.

8. Which of the following PCs should you use to practice making repairs?

A. A Pentium 233 with Windows XP installed

B. A Pentium III in good condition with Windows 98 installed

C. Your own personal PC

D. A 486 in good condition with Windows 9.x installed

9. Which of the following tools has three wire claws that can be extended to pick up and hold parts?

A. Parts retriever

B. Hemostatic forceps

C. Long-nosed pliers

D. Ratchet driver

10. What type of computer retailer can usually offer lower prices because they don’t have the overhead of

storefronts and warehouses?

A. Electronics stores

B. Computer superstores

C. Mail-order vendors

D. Computer dealers

11. What component in the PC poses the greatest danger to you from electrical shock?

A. Hard drive

B. Power supply

C. System board

D. Peripheral device port connector

12. What multifunctional item should be in every PC repair tool kit?

A. Circuit boards

B. Rear vent

C. Floppy drive

D. Paper clip

13. Control and security of PCs, parts, and components in your work area is best achieved by

A. maintaining a complete and accurate log.

B. good physical organization.

C. keeping PCs and components in separate areas.

D. engraving all items with your social security number.

14. An antistatic wrist strap is

A. worn on the dominant hand.

B. essential in protecting you from electrical shock.

C. needed only when working on monitors.

D. used to prevent damage to sensitive electrical components.

15. If an error message is displayed on your monitor during operation of your PC, what should you do first

in an attempt to resolve the problem?

A. Check the manufacturer’s Web site.

B. Check your system documentation.

C. Seek professional assistance.

D. Try changing system settings you think may be related to the problem.

16. Two PC repair technicians are discussing tools. Technician A says that it’s best to buy multiple sets of

less expensive tools in case you lose them. Technician B says that a common slotted screwdriver should be

used for a Phillips-head screw if a Phillips-head screwdriver isn’t available. Which of the following

statements is correct?

A. Neither

B. Only Technician A

C. Both

D. Only Technician B

17. Which of the following is not a cause of a start-up or boot failure on your PC?

A. Monitor resolution set improperly

B. Loose cable

C. Power supply failure

D. Missing or damaged initialization files

18. New Technology File System or NTFS is the

A. method used by DOS to store basic file commands.

B. replacement to the Original Technology File System or OTFS.

C. Windows standard for desktop file and folder arrangements.

D. file system that the Windows NT operating system uses for storing and retrieving files on a hard disk.

End of exam

19. What is the minimum amount of RAM needed to run Windows XP?

A. 1.5 gigabytes

B. 64 megabytes

C. 46 K

D. 32 K

20. Currently, the preferred method for addressing a defective part is to

A. replace the part with a new part.

B. degauss all ports.

C. troubleshoot to motherboard level.

D. send the part to the manufacturer

so be sure that you have seen the entire question and all the answers before choosing an answer.

1. In today’s PC environment, you’re most likely to find floppy drives on

A. legacy or older computers.

B. stand alone networked terminals.

C. smartphones.

D. Kindles and IPADs.

2. Which of the following tasks is not performed by the operating system (OS) of a PC?

A. Formats graphics for Web sites

B. Manages memory

C. Controls input and output devices

D. Prioritizes system requests

3. In Windows 7/Vista, the information that establishes basic settings such as the location of the operating

system and other key startup parameters is located in the

A. Boot Manager (BOOTMGR) file.

B. Boot Configuration Database (BCD).

C. Partition Boot Record (PBR).

D. Boot Initialization (BOOT.INI) file.

4. Utilities software and word processing software are both examples of which of the following?

A. Printer software

B. Desktop publishing software

C. Network software

D. Application software

5. What does BIOS stand for?

A. Basic integrated operating system

B. Basic input/output system

C. Binary instruction override system

D. Backup information only system

6. What does NIC stand for?

A. Network information configuration

B. Network interface cache

C. Network information card

D. Network interface card

7. Which of the following best describes the ink-jet printer?

A. Similar in operation to a dot matrix printer and offers both high quality and affordability

B. Similar in operation to electric or manual typewriters

C. Works the same as a laser printer but uses light-emitting diodes

D. Uses expensive, heat-sensitive paper, is inflexible, and yields a low-quality output

8. The XP boot process was speeded up by which technological innovation?

A. By running boot functions in parallel

B. By locating the BOOT.INI file in its own directory

C. Hardware designed to use higher voltage while running boot routines

D. Microsoft mandated use of dedicated video RAM

9. Which of the following would be the best Internet connection for a person living in a isolated area?

A. DSL

B. Fiber Optic

C. Satellite

D. Cable modem

10. Power supplies in modern computers supply _______ volts.

A. 3.3, 6, and 12

B. 3.3, 5, and 12

C. 3.3, 5, and 6

D. 5, 6, and 12

11. An Internet Service Provider is a company that

A. diagnoses problems with your computer automatically.

B. requires proprietary software available only to paying customers.

C. keeps an inventory of all files on your hard drive.

D. acts as a utility to connect users to the Internet.

12. You should avoid trying to repair a CRT (Cathode Ray Tube) monitor because

A. you’ll void the warranty.

B. high voltages remain in the CRT and can deliver dangerous shocks.

C. the attached PC contains encrypted coding that will be lost.

D. wiring to the PC might short out.

13. Which one of these devices is considered an input device?

A. Monitor

B. Scanner

C. Printer

D. Plotter

14. What type of mouse is becoming the most preferred?

A. Roller ball

B. Optical

C. Mechanical

D. Wheeled

15. Two PC repair technicians are discussing the electrical system of a PC. Technician A says that the

power supply provides electricity to all the devices in a PC. Technician B says that the power supply

supplies 3.3, 5, and 12 volts of AC power. Which technician is correct?

A. Only Technician A

B. Neither

C. Only Technician B

D. Both

16. Which piece of hardware is the computer’s main secondary storage device?

A. Memory address

B. Scanner

C. Monitor

D. Hard drive

17. What operating system uses Fastboot?

A. Windows 7

B. Vista

C. Windows XP

D. Unix

18. All data must be copied into _______ before the CPU can read them.

A. cache

B. ROM

C. BIOS

D. RAM

19. _______ allow the CPU to communicate with external devices or a network.

A. Front ports

B. Alternative slots

C. Expansion cards

D. Portable wires

End of exam

20. The wireless mouse works by

A. Bluetooth connectivity to the CPU

What is quantitative reasoning

Your amazing brain!

Class,

Many people envision something super complex when they hear the term “quantitative reasoning.”  However, you use it every day without even noticing!

Think about the times you have used quantitative reasoning in a typical day at work or at home.  Many times we use historical data (data that we have gathered from past experiences) to build mental models.  Here are some examples of ways that to use quantitative reasoning in a typical day:

1.  Creating my grocery list and buying groceries – This task requires A LOT of quantitative reasoning.  You have to estimate the amount of each item that you need for a given time.  You have to make sure the total of all items fit into your budget.  If you are a comparison shopper or a person who is taking advantage of sales, that requires quantitative reasoning as well.

2.  Estimating what time to leave your house to get to a certain location – If you’re like me and live in a city, this is a task that is performed several times a day at a minimum.  For me, I must consider the weather, road conditions, number of accidents, etc., to make my forecast.

3.  Hearing/reading/seeing the weather report – The weather report each day contains all kinds of quantitative information that must be interpreted so you will know how to dress, what activities might be appropriate for the day, and even how to operate a business.

4.  Setting a meeting – Each time you set a meeting, you must estimate how long the meeting will take.  This is how you know how much time to block off on your calendar at work.

Isn’t it amazing what your brain does?  Most of us don’t even notice that we are constantly making calculations in our heads about everything around us!

Think now…how do you use quantitative reasoning in a typical day?  

1. Which of the following are used to test for the statistical significance or explanatory power of an individual variable?
A) t-statistic
B) p-value
C) t-statistic and p-value
D) R-squared
E) F-statistic
F) R-squared and F-statistic

2. Which of the following are used to test the statistical significance and explanatory power of all the independent variables together (i.e., the explanatory power of the model)?
A) t-statistic
B) p-value
C) t-stastistic and p-value
D) R-squared
E) F-statistic
F) R-squared and F-statistic

3.Which should be used to determine if an individual variable should be added to the regression model?
A) Economic, business or physical theory.
B) The t-statistic and p-value of the variable coefficient.
C) The correlation with other variables included in the model.
D) All of the above.

4.Suppose you have a regression model that depicts the relationship between costs in dollars (C) and the machine hours(H) such that log(C) = 10 + 2(logH). Which of the following is the correct interpretation of the machine hours coefficient?
A) A 1 hour increase in machine use will increase costs by $2.
B) A 1 increase in costs will occur if there is a 2 hour increase in machine use.
C) A 1% increase in machine hours will increase costs 2%.
D) A 1% increase in costs will result from a 2% increase in machine hours.

5.Which of the following is NOT likely to occur when multicollinearity exists in a model?
A) Inflated Adjusted R-squared
B) High correlation between a pair or pairs of variables.
C) A variance inflation factor (VIF) > 5.
D) Theoretically important variables having coefficients that are statistically insignificant.

For this question, none of the options is right. (All the options are true in a model with multicollinearity)

8.2.1: An analyst is evaluating the demand for building and construction materials relative to the cost of borrowing or the mortgage rate in Los Angeles and San Francisco. He believes that the following model is appropriate: Y = 10 + 5X1 + 8X2, where Y is demand in $100 per capita; X1 is mortgage rate in %, and X2 equals 1 if SF, 0 if LA.

6.Given the information in 8.2.1, each additional increase of 1% in the mortgage rate will lead to an estimated average _________________ in demand for building materials, holding constant the effect of city.
A) Increase of $500 per capita.
B) Decrease of $500 per capita.
C) Increase of $5 per capita.
D) Decrease of $5 per capita.

7.Using the model in 8.2.1, the interpretation of the coefficient for X2 is: Holding constant the effect of mortgage rates,
A) Demand for building materials is $800 more per capita in SF than in LA.
B) Demand for building materials is $800 more per capita in LA than SF.
C) Demand for building materials is $8 more per capita in LA than in SF.
D) Demand for building materials is $8 more per capita in SF than in LA.

8.2.2: Advanced Technology Corporation (ATC) manufactures a home computer system and has hired a market research team to analyze the potential demand for this product using historical data on sales of similar products in 66 regions of the country in conjunction with information from consumer surveys. The research firm estimated the following demand function: Q = -36,000 – 10P + 2Px + 300I + 24A – 0.01Asquared, where Q=annual demand in units, P=price of ATC computer ($), Px=price of ATC major competitor computer ($), I = average family disposable income ($100), and A = advertising by ATC ($100).

8.Using situation 8.2.2, the correct interpretation of the coefficient for Px (i.e., +2) is:
A) An increase of computer sales of one unit will occur if there is a $2 increase in the price of the competitor’s computer holding constant P, I, and A.
B) An increase of computer sales of one unit will occur if there is a $200 increase in the price of the competitor computer, holding constant P, I, and A.
C) A $1 increase in the price of the competitor’s computer will increase ATC computer sales by 2 units, holding constant P, I, and A.
D) A $1 increase in the price of the competitor’s computer will increase ATC computer sales by 200 units, holding constant P, I and A.

9.Suppose you review the information in situation 8.2.2 and plan to test the explanatory power of: 1. the overall model and 2. a one-tail test of the individual coefficients, both at the .05 level of significance, then what critical values would you use for your tests? The first answer refers to tests for the model; the second answer refers to the test for the individual variable coefficient.
A) F=2.37 and t=1.671
B) t=1.671 and F=2.37.
C) F=2.25 and t=1.671
D) t=2.00 and F=2.37.

For this question, none of the options is right. (The correct answer is F = 2.52 and t = 1.671)

10.Using situation 8.2.2, what would happen to computer sales if ATC increased the advertising budget by $1000 (check units of measurement before you start to answer)?
A) Sales would increase by approximately 240 units.
B) Sales would increase by approximately 241 units.
C) Sales would increase by approximately 24,000 units.
D) Sales would increase by approximately 14,000 units.