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Correlation

Correlation Analysis: Significance of Correlations

Using the same sample data listed in the Background Response below, calculate the variance of the same sample data, and use that as the population variance. Use the P-Value Method for the calculations. Background: 1. Ask fifteen (15) people to estimate the distance (in miles) from Washington D.C. to New York, New York (sa

Correlation and Regression (Descriptive Statistics)

Finding the Equation of the Regression Line and Making Predictions. In each case, find the regression equation, letting the first variables be the independent (x) variable. Find the indicated predicted values. 1. Tobacco and Alcohol in Children's Movies: Refer to data Set name Children movies and use the times that the

Scatter Diagram Characteristics

A graph that shows the pattern of the relation of two variables is a scatter diagram. How would you define or describe a scatter diagram? When making a scatter diagram, the lowest value on the horizontal axis us usually what value? The overall shape of a scatter diagram should be roughly square. What is the difference between

Methods of Computation and Correlation Lines

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 correlation. Not

Descreptive Statistics - Correlation

A researcher demonstrated a correlation of .60 between teacher attire and student academic performance across 150 grade schools in her state. She concluded that encouraging teachers to be properly attired will increase academic performance. Based on your professional roles, briefly describe three correlational studies you

Correlation/Coefficient

1. Which is the weakest correlation? a. +0.76 b. +0.21 c. -0.01 d. -0.88 2. What would a correlation of .35 would be called? a. Moderate b. Weak c. Very Strong d. Very Weak 3. Which correlation coefficient indicates the strongest relationship? a. 0.00 b. +0.50

Point Biserial Correlation

To test the effectiveness of a new studying strategy, a teacher randomly divides a sample of 8 students into tow groups, with n = 4 in each group. The students in group one receive training in the new studying strategy. Then all students are given 30 minutes to study a chapter before taking a quiz. The quiz scores for the t

Cholesterol and Body Mass Index

Cholesterol and Body Mass Index: use the following data set below and use the cholesterol levels (x) and body mass index values (y) of the 40 women. a.Based on a scatter plot, describe the relationship between the variables. b.Find r-squared and use it to determine the value of the correlation coefficient. Is the correl

Which types of analysis does human service research use the most?

The researcher usually conducts one of 3 types of analysis, a statistical comparison, correlation or predictions. Each of these techniques provides a unique perception of the findings. Which technique do you think is used most often in human service research and why?

Sample correaltion coefficient

The number of convertibles sold at a car dealership in a month and the average monthly temperature (in degree Fahrenheit) are given in the Table below : Convertible sold, x 0 2 6 5 7 9 Average monthly temperature, y 40 48 58 62 72 79 Find the sample correlation coefficient r? Determine whether there is a positive

Finding sample correlation coefficient

Problem: For major league baseball teams, Is there any relationship between player payroll and mean attendance? Player Payroll Mean Attendance 1000,000 in thousands X Y Anaheim 62.8 28.52 Balfimore 56.5 33.09 Boston 110.2

Linear correlation coefficient

Given the following ordered data pairs (x, y), compute the value of the linear correlation coefficient r: (2,6) (3,0) (5,15) (5,5) (10,2). Give the value to 3 significant digits.

Scatter diagram and correlation coefficient

Below are the gestation days and longevity for 22 animals. a) Make a scatter chart. b) Calculate correlation coefficient and interpret it. c)Test the correlation coefficient for signficance. Clearly stating the degrees of freedom. Animal Gestation (Days) Longevity (Years) Ass 365 12

Correlation, Causation, Independent & Dependent Variables

1. Does correlation equal causation? Does the strength of correlation depend on the direction? What is the meaning of a zero correlation? Explain your answers. 2. What is the difference between an independent and a dependent variable? Does a regression model imply causation? Why or why not? 3. How can you use correlation

Scatterplots Correlation for Data Analysis

Use the following situation to answer questions 14 to 18 below: A meteorologist wants to see if there is a relationship between the number of toronados that occur each year and the number of deaths attributed to the tornadoes. The data are shown for 10 recent years. The number of tornados is represented by x, and the numb

Correlation coefficient

Please see the attached file. 10. An agronomy study was performed to compare the yield (in kg/ha) of Sundance winter wheat and Manitou spring wheat under the same conditions. Listed below are actual yields of both varieties of wheat from nine test plot locations. Using a 5% significance level, is there statistically suffici

Scatter diagram, covariance, correlation, weighted average

45. Nielsen Media Research provides two measures of the television viewing audience: a television program rating, which is the percentage of households with televisions watching a program, and a television program share, which is the percentage of households watching a program among those with televisions in use. The following d

Determining Correlation of Datasets

Can you provide an example using your own data set (two related and unrelated variables) of at least twenty numbers each and apply the formula of correlation. Determine the correlation of each of the two sets of data. Is the correlation positive or negative? Can you explain what this means? Can you explain the difference bet

Inferential Statistics and Linear Correlation

A study was conducted with alpha = 0.05 to determine if there is a significant linear correlation between the number of credit hours earned at the time of taking statistics 101 and the grade in the course. Eight pairs of data were collected. The linear correlation coefficient is y = 0.6777 Pick the correct answer a. T

Correlation and Prediction

1. What statistic do you use to precisely describe a correlation? 2. Why is the regression line "the line of best fit"? 3. What are the properties of Z scores and the Z distribution? 4. Why do you study samples and not populations?

More appropriate variable to replace one of the two variables.

We must use common sense when we analyze data and discover correlation exists. A large value for a correlation coefficient does not necessarily mean that real correlation exists. One of the classic examples is the study that discovered a high correlation between the increased use of illegal drugs by high school students and th

Practical Application of Correlational Research in the Workplace

Share the practical applications of the study from the Unit 2 Individual Project. How would the results of this survey be used in the workplace? Briefly describe co relational research. Name a variable from this study and one from the workplace that might prove to provide a co relational relationship and explain why you would

Random Variable Problem

The total population of car passengers involved in traffic accidents are classified into six categories: two factors (one with 2 levels and one with 3 levels) crossed. The first factor is: Survivors (X1=0), Fatalities (X1=1). The second factor is: No Belt (X2=0), Adult Belt (X2=1), and Child Seat (X2=2). The proportions are as f

Correlations, Correlation Coefficient, and Random Variables

Please help with the following problems. 1. Describe the correlation in this graph (see graph in attachment) 2. Which of these is true for the correlation coefficient? - its range is [-1 1] - we use r to represent it - we use r^2 to represent it - both 1 and 2 - both 1 and 3 3. Indicate whether the random variabl

WidgeCorp: Simple and Multiple Correlation and Regression

You're in a brainstorming session at WidgeCorp, where no idea is too outrageous. You're discussing penetration in the school lunch market. Ideas around school lunch subsidies, Internet subsidies, and Internet target marketing are being discussed. As the end of the meeting, the group asks you to prove or disprove some assumptions

Correlation Coefficient - least square regression

A movie studio wishes to determine the relationship between the revenue from rental of DVDs and videotapes of comedies and the revenue generated from the theatrical release of such movies. The studio has the following bivariate data from a sample of fifteen comedies released over the past five years. These data give the revenue

Distinction between the Pearson and Spearman correlations

1. What information is provided by the sign (= or -) of the Pearson correlation? 2. What information is provided by numerical value of the Pearson correlation? 20. What is the major distinction between the Pearson and Spearman correlations? 10a. A professor obtains SAT scores and freshman grade point averages (GPAs) for a

Correlation

? Explain how correlation is often miscast as causation. Specifically, as it relates to how cause is attributed to a variable when in fact, there is no causal relationship but only a correlation between the two variables. ? Give an example of correlations. ? Using the example, describe how correlation might be interpreted i