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Measures of Association: Covariance and Correlation

See attached file. There are several methods for calculating fuel economy. Go to the Resources section in this syllabus and open the file mileage.xls. The table in the file indicates the mileage, as calculated by owners and by current standards. 1. Compute the covariance. 2. Compute the correlation coefficient. 3. Which

Correlation of body measurement

Please see attachment 3)use a technology tool to find the regression line for each pair in exercise 1 that has a strong correlation 4)use the result of exercise 3 to product the following a)the neck circumference for a man whose weight is 180 pounds b) the abdomen circumference of a man whose hip circumference is 100 ce

Correlational and comparative data sets: statistical tests and conclusions

Analyze and Report Correlational and Comparative Data Sets · Analyze the following two data sets: [see attached file] · Prepare a report on the two different types of analyses: correlation and comparison, using the questions associated with the two data sets. Address the following for each analysis: o

Rank Correlation for Car Fuel Consumption

Car Fuel Consumption Listed below are the highway fuel consumption amounts (in mi/gal) from cars in three different categories. Use a 0.05 signifiacance level to test the claim that the different car categories have the same median highway fuel consumption. Based on the results, does the number of cylinders appear to affect h

Correlations and T-Tests: Example Problem

A) What does it mean when it is said that two variables have no correlation? B) What is the connection between correlation and the t Test? C) How is the strength of a correlation determined?

Statistics Scatter Diagram

11. Make up a scatter diagram with 10 dots for each of the following situations: (a) perfect positive linear correlation, (b) large but not perfect positive linear correlation, (c) small positive linear correlation, (d) large but not perfect negative linear correlation, (e) no correlation, (f) clear curvilinear correla

Correlation and regression - total variation

Refer to the minitab display obtained by using the paired data consisting of weights (in lb) of 32 cars and their highway fuel consumption amounts (in mi/gal). Along with the paired sample data, minitab was also given a car weight of 4000 lb to be used for predicting the highway fuel consumption amount The regression equation


John, a medical practitioner at a private medical facility, is discussing the problem that one of his patients, Tom, says he has been having with the medication that the doctor has prescribed. It is a new medication and the facility has been asked to gather information about the medication for the manufacturer. At a previous vis

Statistics: Coefficient of correlation, scatter diagram, regrression equation

See attached file for full problems. 1. What is the relationship between the amount spent per week on food and the size of the family? Do larger families spend more on food? A sample of 10 families in the Chicago area revealed the following figures for family size and the amount spent on food per week. See attached file f

Classifying strength of correlation

If +.75 represents a "strong" positive correlation, where does the concept of a "strong" correlation begin? For example, is +.67 a strong correlation? How about .5? How about .42? How about .3?

Hypothesis tests for Correlation Coefficient

A nationwide standardized test taken by high-school juniors and seniors may or may not measure academic potential, but we can nonetheless examine the relationship between scores on such tests and performance in college. We have chosen a random sample of 105 students just finishing their first year of college, and for each st

Statistics: 20 MCQ on ANOVA, correlation, hypothesis testing etc.

Question 1: For an experiment comparing more than two treatment conditions you should use analysis of variance rather than separate t tests because: conducting several t tests would inflate the risk of a Type I error. separate t tests would require substantially more computations . a test based on variances is more sensiti

Statistics Practice problems

11-59. Marketers know that tastes differ in various regions of the country. In the rental car business, an industry expert has given the opinion that there are strong regional preferences for size of car and quotes the following data in support of that view: Region of Count

Statistics Correlations for Absences and Final Grades

1. You are given the following data. Number of Absences Final grades 0 96 1 91 2 78 2 83 3 75 3 62 4 70 5 68 6 56 a. Make a scatter plot for the data. You do not need to turn this in, but based on your scatterplot, does it look like the correlation is significa

Correlation: wish to determine the correlation between the height (in inches) and weight (in pounds) of 21-year-old males... 3. All but one of the following statements contains ... 4. I want to examine the relationship between gas mileage of cars and the engine size ... 8. A statistics student computes the correlation between two variables in her spreadsheet, and finds ...

2. I wish to determine the correlation between the height (in inches) and weight (in pounds) of 21-year-old males. To do this, I measure the height and weight of two 21-year-old men. The measured values are The correlation r computed from the measurements on these males is A. 1.0 B. -1.0 C. near 0 because the heights

Correlation coefficient r

For the following data calculate the correlation coefficient r and make a conclusion about the type of correlation. The number of hours 6 students watched T.V. during the weekend and the scores of each student who took a test the following Monday. Hours spent watching TV, X 0 1 2 3 3 5 Test Scores, Y

Correlation coefficient r

Calculate the correlation coefficient r, letting Row 1 represent the x-values and Row 2 the y-values. Then calculate it again, letting Row 2 represent the x-values and Row 1 the y-values. What effect does switching the variables have on r? Row 1 20 26 34 43 51 69 72 Row 2 165 144 112 180 20

Statistical Methods

Why might a researcher want to use multivariate analysis rather than a univariate or bivariate analysis technique?

Correlation Matrix for a Company's Sales

A correlation matrix (correlation coefficients and probability level under the hypothesis rho=0) for a company's sales force (age, years of service, and current sales) is given below. Comment. Age Years of Service Current Sales Age

Find the correlation

I need help in doing these 2 equations step-by-step or if it is done in excel could you please explain how? ------------------------------------------------- #1 For the last 6 years, I have kept fairly detailed data on wind speed and the resultant hull speed of my sailboat. Here is the windspeed-hullspeed data


Bi-lo Appliance Super Store has stores in several metropolitan areas of New England. The sale general manager planning to deliver a digital camera commercial for a local television station before a sale that begins Saturday and ends on Sunday. Plans to obtain information for the sales of the digital camera during the Saturday an

The Correlation Coefficient at a Particular Significance Level

1. A math teacher believes there is a correlation between a student's Exam I score (x) and the Final Exam score (y). Below is the test data (although Jean's scores were blotted out by accident) and the summations from all the students' scores in the class. Determine the appropriate correlation coefficient, r, and whether there i

Linear relationship and the sample correlation coefficient

In which data set is there evidence of a strong nonlinear relationship between the two variables? (x,y u,v w,t m,n no data sets at all) Which data set indicates the strongest positive linear relationship between its two variables? (x,y u,v w,t m,n) Which data set has an apparent negative, but not perfect linear rela

Covariance and Correlation Calculations

Covariance and Correlation. Show all work in computing the covariance and coefficient of correlation for the data set: (-1,10), ( 3,9), (5,7), (9,2). (nearest 0.01) sxy = _______________ r = ________________ Simple Linear Regression. 1. Consider t

Analyzing Bivariate Relationships

1. For the following data on 10 persons, construct a scatterplot showing the relationship between age and number of children, and describe the relationship in verbal terms. Person (i) Age (X1) Number of Children (Yi) 1 42 5 2 26 2 3 38 2 4 23 1 5 21 0 6 19 0 7 79 6 8 25 2 9 75 4 10 67 3 2. Suppose social psycho

Correlation analysis

Given the data below, 8 100 5 85 6 89 4 60 3 50 1 20 From a data analysis regarding the Correlation feature the following results were obtained. Column 1 Column 2 Column 1 1 Column 2 0.969486 1 Describe what the results mean for this data set?

T test for Correlation coefficient

A correlation coefficient for Bee Taylor's Department Store in Mayberry, NC, between sales ability and amount of sales is Sales ability is measured on an interval scale and amount of sales is measured on a ratio scale. Note that the correlation was conducted on 42 sales employees. Test this coefficient by using a t test and

Correlation Coefficient and Determination- Schering-Plough Corporation

Listed below are the net sales for Schering-Plough Corporation (a pharmaceutical company) and its subsidiaries for the six years from 1997 to 2002. The net sales are in millions of dollars. Year Net Sales 1997 $ 6,714 1998 7,991 1999 9,075 2000 9,775 2001 9,762 2002 10,180 a. Determine