Question


    Tutorial

    Category :Math/Stat Homework

    Posted By:AccountingExpert

    Price Offered : $25

    Posting Date : 2014/06/29 01:14

    Due Date : 2014/06/30 12:00

    Answered (1 time)

    More Questions Like This



    QSO 510 Quantitative Analysis

    Midterm Exam

     Instructor

    This exam consists of 6 parts (points for specific portions of each section are indicated).  Finish your answers, and return the exam within three hours. This exam is open book and open notes individual work. No collaboration or help from others are allowed. Remember the following exam instructions:

    1.     Show ALL Steps including formulas used and all calculations done to arrive at the final answers. Incomplete solutions will receive partial credit.

    2.     Answer all questions in the context of the problem. General answers are not expected.

    3.     Use at least four significant digits at all intermediate steps. Round off the final answers appropriately. Note: 0.0042 is only two significant digits as leading zeros are not considered significant. Trailing zeros are considered significant.

    4.     Questions are welcome. If your question relates to the solution of a problem, it may not be answered by the instructor.

     

    Final Exam

    Points Earned

    True or False

     

    Multiple Choice

     

    Problem 1

     

    Problem 2

     

    Problem 3

     

    Problem 4

     

    Total

     

     

    The Honor Pledge:

     

                On my honor, I have neither given nor received unauthorized aid on this examination. 

                                                                                                                                       

     

     

     

    __________________________                     Good Luck!

           Student Name (Signature)

    True or False. (2 points × 5 = 10 points)

    Write T or F in the parentheses in the front of each question.

    1.      (                 ) The Central Limit Theorem states that the sampling distribution of sample means will always follow a normal distribution regardless of sample size .                                                                                                                                   True               False

     

    2.     (                 ) In hypothesis testing, the Null hypothesis represents what we want to prove wrong.                                                                                                   True               False

     

    3.     (                 ) In regression analysis, we prefer bigger coefficient of determination ().                                                                                                                     True               False

     

    4.     (                 ) Any sampling methods will guarantee representation of the population as long as there is some randomness involved.                                                                                                                                                                                                True               False

     

    5.     (                 ) In hypothesis testing for population mean , the test statistics we choose depends on whether or not we know the population standard deviation. A  statistic should be chosen if we DO know the population standard deviation .                                                                                                                                             True               False

     


     

    Multiple Choice. (2 Points × 5 = 10 Points)

    Circle the most appropriate answer clearly.

    A manager of a car dealership believes that there is a relationship between the number of salespeople on duty and the number of cars sold. Suppose the following sample is used to develop a simple regression model to predict the number of cars sold by the number of salespeople.

     

    Number of Salespeople

    ()

    Number of Cars Sold

    ()

    6

    79

    3.24

    655.36

    46.08

    6

    64

    3.24

    112.36

    19.08

    4

    49

    0.04

    19.36

    0.88

    2

    23

    4.84

    924.16

    66.88

    3

    52

    1.44

    1.96

    1.68

    12.8

    1713.2

    134.6

     

    Answer Questions 1-5 based on the above problem statement.

     

    1.     (                ) What is the standard deviation of the Number of Salespeople (X)?

     

                A. 4.2                           B. 12.8                        C. 1.789                      D. 1.6

     

    2.     (                 ) What is the slope of the regression line ?

     

                A. 12.71                      B. 133.8                      C. 32.08                      D. 10.52

     

    3.     (                 ) Estimate the number of cars sold () when the number of salespeople (X) is 5?

     

                A. 50.2                        B. 61.8                        C. 58.3                         D. 60.5

     

    4.     (                 ) Choose the right formula to construct a 95% confidence interval for the number of cars sold () when the number of salespeople (X) is 5?

     

    A.                                              B.                   

    C.                                                   D.           

     

    5.     (                 ) Find the coefficient of determination  for this simple regression model?

     

                A. 0.7854                    B. 0.8265                    C. 0.8812                    D. 0.9020

    Problem 1. (20 points)

    The amount of time a bank teller spends with each customer has a population mean  minutes and population standard deviation  minute.

     

    a)    If a customer is randomly selected, what is the probability that the service time would exceed 3 minutes?

    b)    If many samples of 64 were selected, what are mean and standard error of the mean (standard deviation of the sample means) expected to be? What is the expected shape of the distribution of sample means? Justify your answer.

    c)     If a random sample of 64 customers is selected, what is the probability that mean service time would exceed 3 minutes?

     

     

     


     

    Problem 2. (20 points)

     

    The customer service department of a local gas utility company would like to estimate the average length of time between the entry of service request and the connection of service called the response time. A random sample of 5 houses was selected from the records available during the past year. The results in number of days are displayed below:

     

    11, 12, 9, 10, 13

     

    a)    Compute the sample mean and sample standard deviation of the response time.

     

    b)    Construct a 95% confidence interval for the average response time for all customers requesting connection of service. 

     

    c)     How would you explain the confidence interval for the response time to the President of the company? Provide a clear and complete answer. Use actual variable names and numbers in your answer. Do not use words like “population” in your answer that the president may not understand.

     

     

     

     


     

    Problem 3. (20 points)

     

    In an attempt to determine whether or not special training increases the speed with which assembly line workers can do an assembly job at AMTEL Inc., 25 workers are timed performing the task. Then, they are given a special training course designed to increases their assembly efficiency. At the end of the course, they are timed doing the same task. The differences between the first and the second time are recorded for each of the 25 assembly line workers. The mean improvement for the 25 workers was found to be 2.6 minutes and the sample standard deviation was 4 minutes.

     

    Let variable  represents the improvement in time for each assembly line worker. Let  represents the average improvement in time for the population. Has the training improved the time required on the job? Please test the hypothesis use  as the level of significance. (Hint:  meaning that the training improves the time.  Please follow the 7 step procedure!)

     


     

    Problem 4. (20 points)

     

    Consider the following time series data representing quarterly sales of dishwashers at Big Boys Appliances over the past two years:

     

    Time

    Sales

    2010 Quarter 1

    25

    2010 Quarter 2

    85

    2010 Quarter 3

    64

    2010 Quarter 4

    30

    2011 Quarter 1

    70

    2011 Quarter 2

    125

    2011 Quarter 3

    105

    2011 Quarter 4

    90

     

    The scatter plot of the data above shows seasonality with trend. Hence, a multiple regression model is run to forecast the demand. We denote sales (Y) as the depend variable, and denote time (t, with  represent the first quarter of 2010) and dummy variables (, , and ) as independent variables. Here, we choose quarter 1 as the baseline and adopt three seasonality dummy variables, such that  represents quarter 2,  represents quarter 3, and  represents quarter 4. Answer the following questions. Use

     

    a)    (5 points) Use the above variable definition to code the data above.

     

    Time

    Sales(Y)

    Time (t)

    2010 Quarter 1

    25

    1

     

     

     

    2010 Quarter 2

    85

    2

     

     

     

    2010 Quarter 3

    64

    3

     

     

     

    2010 Quarter 4

    30

    4

     

     

     

    2011 Quarter 1

    70

    5

     

     

     

    2011 Quarter 2

    125

    6

     

     

     

    2011 Quarter 3

    105

    7

     

     

     

    2011 Quarter 4

    90

    8

     

     

     

     

     

     

     

     

    b)    (5 points) Copy the data into Excel and run the corresponding multiple regression. Write the estimated multiple regression equation use the variables defined above. (Hint: No need to conduct backwards elimination at this point.)

     

     

     

     

     

     

    c)     (5 points) Explain the meaning of the slopes for seasonally dummy variable , , and . (Note: Use actual variable name and numbers to answer the questions. Put numbers in the right context.)

     

     

     

     

     

     

     

     

    d)    (5 points) Test the overallfitness of the model. (State the hypotheses, and use Significant F to complete your test.)

     

     

     

     

     

     

     

     

     

     

     

    e)    (Bonus 5 points) Which variables in the current regression model are significant? And which are not significant? Justify your answer.

     

     

     

     

     

     

    Answer
    Submitted by AccountingExpert on 2014/06/29 01:15
    teacher rated 211 times

    Price: $25.00

     

    Qso510 Midterm Exam 100% Correct Detailed Tutorial Top Level solution A+++Solution Guide




    ---- file 1.docx preview (839 words)---

    xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx whether xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx assembly xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx Inc., xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx are xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx assembly xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx timed xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx and xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx 25 xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx workers xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx standard xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx improvement xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx represents xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx the xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx test xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx (Hint: xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx Please xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx test xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx job xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx are,H0: xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx will xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx on xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx right xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx we xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx size xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx t xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx = xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx = xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx that xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx thus xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx

    - - - more text follows - - -



    Login or Register to buy answer

    Down payment will be adjusted against total price. You can see full view of answer or download document after purchase.

    Social Share