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    Correlation and Regression Analysis

    Step-wise answer to Statistics - All Topics

    An expert witness in a case of alleged racial discrimination in a state university school of nursing introduced a regression of the determinants of Salary of each professor for each year during an 8-year period (n = 423) with the following results, with dependent variable Year (year in which the salary was observed) and predicto

    Correlation coefficient - A Pearsons Correlation coefficient between college entrance exam grades and scholastic achievement was computed on a very sophisticated computer program to be -1.08. The USAF has asked you to comment on the researchers methodology and findings. On the basis of your brief study, you would tell the USAF that:

    A Pearsons Correlation coefficient between college entrance exam grades and scholastic achievement was computed on a very sophisticated computer program to be -1.08. The USAF has asked you to comment on the researchers methodology and findings. On the basis of your brief study, you would tell the USAF that:

    Determining Coefficients in Regression Analysis

    The following sample observations were randomly selected. Please see the attached file. Determine the coefficient of correlation and the coefficient of determination. Interpret the association between X and Y.

    The production department of NDB Electronics wants to explore the relationship between the number of employees who assemble a subassembly and the number produced. ... [See thee attached question file.]

    2. The production department of NDB Electronics wants to explore the relationship between the number of employees who assemble a subassembly and the number produced. As an experiment, two employees were assigned to assemble the subassemblies. They produced 15 during a one-hour period. Then four employees assembled them. They pro

    The owner of Maumee Ford-Mercury wants to study the relationship between the age of a car and its selling price. Listed below is a random sample of 12 used cars sold at the dealership during the last year. ... [See the attached questions file.]

    Please calculate and answer this question step by step. 1. The owner of Maumee Ford-Mercury wants to study the relationship between the age of a car and its selling price. Listed below is a random sample of 12 used cars sold at the dealership during the last year. a. If we want to estimate selling price on the basis of

    Using a Causal Model (Regression)

    Strayer administrators believe the number of applications is influenced by tuition. The following data for an 8-year period show tuition rates and the size of the applicant pool. Tuition Applicants $ 900 11060 1250 1090 1375 8670 1400 9050 1550

    Linear programming problems:Graphical methods

    In the following two problems: Provide the extreme points of the feasible region in the form of (x1 = , x2 = , Z = ) and identify which is the optimum solution. You need not list the origin as an extreme point, because it is a given. List the extreme points of the feasible region and indicate one of the following: (1) th

    Sally's Software: Logarithmic Trend Equations and Sales Increase

    Sally's Software, Inc. is a rapidly growing supplier of computer software to the Sarasota area. Sales for the last five years are provided in the attached document. a. Determine the logarithmic trend equation. b. By what percent did sales increase, on the average, during the period? c. Estimate sales for the year 2003.

    The Least Squares Trend Equation and Estimate Vending Sales

    Please see the attached file for the full question. The amounts spent in vending machines in the United States, in billions of dollars, for the years 1997 through 2001 are given below. Determine the least squares trend equation, and estimate vending sales for 2003.

    Plotting Data and Forecasting

    14.16 (a) Plot the data on U.S. general aviation shipments. (b) Describe the pattern and discuss possible causes. (c) Would a fitted trend be helpful? Explain. (d) Make a similar graph for 1992-2003 only. Would a fitted trend be helpful in making a prediction for 2004? (e) Fit a trend model of your choice to the 1992-2003 data.

    U.S. General Aviation Shipments

    (a) Plot the data on U.S. general aviation shipments. (b) Describe the pattern and discuss possible causes. (c) Would a fitted trend be helpful? Explain. (d) Make a similar graph for 1992-2003 only. Would a fitted trend be helpful in making a prediction for 2004? (e) Fit a trend model of your choice to the 1992-2003 data. (f) Ma

    Net Worth of Sponge Bob

    Listed below is Sponge Bob's net worth from 1998 to 2007 (see the attached file). Determine the least squares trend equation. Interpret the slope. Estimate Sponge Bob's net worth for year 2010.

    Linear Programming Model

    Lij Systems is an electronics company with production facilities located in Atlanta, Boston, and Chicago. Components produced at these facilities may be shipped to the firm's regional warehouses that are located in Edison and Fargo. From the warehouses the firm supplies retail outlets located in Houston, Indianapolis, and Jackso

    Scatter Diagram of Craft Fairs and Exhibitors

    Mary Sue wants to know if there is a connection between attendance at craft fairs and the number of exhibitors who have booths at the fair. For a random sample of seven local craft fairs, she chose a random day of the fair and recorded the number of exhibitors. In the data below, x represents the number of exhibitors and y repr

    Scatter Diagram for least-square lines

    In a random sample of eight military contracts involving cost overruns, the following information was obtained. x = big price of the contract (in millions of dollars) and y = cost of overrun (expressed as a percent of the bid price). x 6 10 3 5 9 18 16 21 y 31 25 39 35 29 12 17 8 a) Draw the scatter diagram for this da

    Predicted Output

    The following equation describes the relationship between output and labor input at a sample of work stations in a manufacturing plant: 'y = 2.35 + 2.20x. Suppose, for a selected work station, the labor input is 5. The predicted output is _____________.

    Residual Observation

    Using the line speed of a conveyor belt to predict the number of defective parts we are given an intercept of 22.17 and a slope of -.148, use the data below to calculate the residual for observation #4.

    US Gasoline Market Slope Coefficient, Demand Equation

    This file includes annual data on the U.S. Gasoline market from 1953 to 2004. ? Quantity is U.S. Finished Motor Gasoline Product Sold (in Thousands of Barrels) ? Pop is U.S. total population in thousands, ? GasPIndex is the average nominal price for gasoline, in the form of an index, ? Income is a measure of personal

    Predicting Life Expectancies from Birth Rates

    See the attachment for full problem description. Might we be able to predict life expectancies from birthrates? Below are bivariate data giving birthrate and life expectancy information for each of twelve countries. For each of the countries, both, the number of births per one thousand people in the population, and, the fem

    Solving a Simple Regression Problem

    The material is from A SIMPLE REGRESSION PROBLEM. Please use any computer software to solve the problem if you want. Please provide the evidence of your work and explain your solution. Thank you.

    What Does δ Represent in the Regression Model?

    (a) What does δ represent in the regression model? (b) What assumptions do we make about δ (epsilon)? What is the distinction between Greek letters (β - beta) and Roman letters (b) in representing a regression equation?

    Inferential Statistics and Regression Equation

    A computer utility was applied to the data collected in a study of generalized health index as a function of weight/height ratio, cholesterol and average nightly sleep. Part of the output is shown below. Find the regression equation. Predictor Coef SECoef T P constant 60 6.431 7

    Least-Squares Method and Coefficient of Determination

    The director of graduate studies at a large college of business would like to predict the grade point average (gpa) of students in an MBA program based on Graduate Management admission test (GMAT) scores. A sample of 20 students who had completed 2 years in the program is selected. The results are as follows: Observation G

    Analyzing the Relationship Between Time and Quality

    The data in the attached file is from a study conducted to examine the quality of fish after 7 days in ice storage. Ten fish of the same type and approximately the same size were caught and prepared for ice storage. Two of the fish were put in storage immediately after being caught, two were placed in storage 3 hours after be