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# Correlation

### Scatter diagram and correlation

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 produc

### Negative correlation

After plotting the data point s on a scatter diagram, we have observed an inverse relationship between the independent variable (X) and the dependent variable (Y). Therefore, we can expect both the sample slope and the sample __________ to be a negative value.

### Study Questions for Exam

1. Suppose the expected returns and standard deviations of stocks A and B are E(RA) = 0.17, E(RB) = 0.27, StdDevA = 0.12, and StdDevB = 0.21, respectively. a. Calculate the expected return and standard deviation of a portfolio that is composed fo 35 percent A and 65 percent B when the correlation between the returns on A and

### Test of Correlation Coefficient

1. The following hypotheses are given H0: rho = 0 H1: rho > 0 A random sample of 12 paired observations indicated a correlation of .32. Can we conclude that the correlation in the population is greater than zero? Use the .05 significance level. 2. The Pennsylvania Refining Company is studying the relationship between the

### Correlation between retail online sales and total retail sales

My product development team is wondering if there is a correlation between retail online sales and total retail sales. I must work with the peer/mentor group to calculate the correlation between online and total retail sales, and interpret the results. If my peers are struggling with the calculations, I should share examples and

### Multiple Choice Questions: correlation, one-way ANOVA, smoking cessation study

13. A friend of yours says to you-- I know you're going to work with people with mental problems but aren't you worried that you might be attacked or stalked or something? I mean after all I saw on the news last year about that psychologist who was killed by her client. You talk with your friend about the topic and then decide

### Research and Evaluation: correlation between 3 pairs of variables

Please need help with this. Can you please give few easy examples. Provide three pairs of variables (three dependent and three independent) that we believe are correlated with one another. State the reason for believing there is a correlation between the variables and in what direction we believe the correlation would b

### Spearman's coefficient of rank correlation

16-26. Far West University offers both day and evening classes in business administration. One question in a survey of students inquires how they perceive the prestige associated with certain careers. Each student was asked to rank the careers from 1 to 8, with 1 having the most prestige and 8 the least prestige. The results wer

### Nonparametric Method: Analysis of Ranked Data Problem

Nonparametric Method: Analysis of Ranked Data Far West University offers both day and evening classes in business administration. One question in a survey of students inquires how they perceive the prestige associated with certain careers. Each student was asked to rank the careers from 1 to 8, with 1 having the most prest

### Determining the Correlation Coefficient

Calculate the correlation between age and tenure with the company. Explain results. I have worked up the data below, but am not really sure how to correlate it. First, how do I determine which is the predictor and which is the response variable? Tenure Age <2 yrs 2 to 5 yrs >5 yrs Total 21 & under 20 26 2 48 % T

### Statistics: Variables, Scatterplot and Correlations

Question: 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. Car Age (years) Selling Price (\$000) Car Age (years) Selling Price (\$000) 1 9

### Predictions on Mouse Numbers

The average number of mice per home in Canada is 5.7 and s = 1.2. The average number of packages of mouse killer used per family per year is 4.2 and s = 1.1. The correlation between mice in the home and mouse killer bought is .5. The Cat family bought 12 packages of mouse killer last year. How many mice would you predict th

### Coefficients of Correlation and Determination

The production department wants to explore the relationship between the number of employees who assemble a subassembly and the number produced. The complete set of paired observations follows: Number of Assemblers One Hour Production (units) 2 15 4 2

Analyze the following data based on 2000 U.S. Census Data and American Cancer Society data: Cancer death rate - both sexes (all forms of cancer) per 100,000 (1998-2002): District of Columbia: 238.7 Kentucky: 226.9 Utah: 150.6 USA: 197.8 Lung cancer rates - both sexes (per 100,000) (1198-2002): District of Columbia:

### Linear Regression and Correlation for Supermarket Income

Super Markets Inc is considering expanding into the Scottsdale Arizona area.MS Luann Miller,Director of Planning,must provide an analysis of the proposed expansion to the operating committee of the board of directors. As a part of her proposal,she needs to include information on the amount of people in the region spend pre month

### Spearman's Coefficient of Rank Correlation

Far West University offers both day and evening classes in business administration. One question in a survey of the students inquires how they perceive the prestige associated with certain careers. Each student was asked to rank the careers from 1 to 8, with 1 having the most prestige and 8 the least prestige. the results were a

### What does a coefficient of correlation of .70 mean?

What does a coefficient of correlation of .70 mean? a. Almost no correlation because .70 is close to 1.0 b. 70% of the variation in one variable is explained by the other variable c. Coefficient of determination is 0.49 d. Coefficient of nondetermination is 0.30 e. None of the above

### Maumee Ford-Mercury Statistics Questions

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 last year (see attached file): a. If we want to estimate selling price on the basis of the age of the car, which variable is the depende

### Correlation versus Risk

Investment reports often include correlations. Following a table of correlations among mutual funds, a reporter adds, "Two funds can have perfect correlation, yet different levels of risk. For example, Fund A and Fund B may be perfectly correlated, yet Fund A moves 20% whenever Fund B moves 10%." Write a brief explanation, fo

### Statistics: Correlational Research

Share the practical applications of the study (male=120 and female =168). How would the results of this survey be used in the workplace .Briefly describe correlational research .Name a variable from this study and one from the workplace that might prove to provide a correlational relationship and explain why you would choose the

### Correlation and causation

These questions are addressed to a specific study and database which I am not including in order to prevent the apperance of asking for assignment completion however it is worth mentioning that the study is one about job satisfaction and the variables involved are age, gender, tenure and department and the units of measure are o

### Positive Correlation Between Financial Institutions' Assets and Pretax Profit

A study of 20 worldwide financial institutions showed the correlation between their assets and pretax profit to be .86. At the .05 significance level, can we conclude that there is positive correlation in the population?

### Correlation Coeffcient

Sabin Motorcycle Works plans to develop a brochure for its new revolutionary X2B cycle. One of the facets to be explored and reported on is the speed-mileage question: Is there a linear relationship between the cycle's speed and miles per gallon? Tests on their track revealed the following: Constant speed

### Correlation or relationships

The quality control department at Food Town Inc, a grocery chain in upstate New york, conducts a monthly check on the comparison of scanned prices to posted prices. The chart below summarizes the results of a sample of 500 items last month. Company management would like to know whether there is any relationship between error rat

### Correlation Coefficient Of Linear Functions

Let X1, X2, and X3 be random variables with equal variances but with correlation coefficients rho12=0.3, rho13=0.5, and rho23=0.2 Find the correlation coefficient of the linear functions Y=X1+X2 and Z=X2+X3.

### Linear regression model: The results of a casual linear regression model were Y = 0 + 1.95 X. What would the correlation coefficient, r, be?

The results of a casual linear regression model were Y = 0 + 1.95 X. What would the correlation coefficient, r, be? Please explain. Thank you.

### Testing correlation for significance.

In both cases, give a number of data points, n, and a correlation coefficient, r. Draw a number of data points, n, and a correlation coefficient, r. Tell whether the correlation is significant at 0.05 or 0.01 level, explain. n=50 points, r=0.35. n=20 points, r=0.58.

### Critical values for testing correlation (r^2)

1. The IQ scores of 30 children from under-privileged households, were measured before and a year after, a program of nutritional supplementation was instigated at a primary school. Use a two-tailed test. Is there an effect of nutritional supplementation? Submit your answers on a standard answer sheet. (e) Given a (alpha)

### correlation between degree of loneliness and hours of TV watched

Professor turner found that the correlation between a person's degree of loneliness and the number of hours watching TV is -0.69. He can conclude that... a. As we observe people with higher levels of loneliness, we see a tendency for those people to spend less and less time watching TV. b. There is not much of a relatio

### correlation coefficient ranges

Suppose you find a restriction in your study of IQ scores and school achievement at a selective private school. Restricting the range is likely to do what to the correlation coefficient? a. Increase the size b. Underestimate the strength c. Have no effect d. Change the sign