Reference no: EM133196997
Correlation and Regression
DQ1: It is sometimes said that the higher the correlation between two variables, the more likely the relationship is causal. Do you think this is correct? Discuss.
DQ2: Discuss the strengths and weaknesses of correlational and regression studies; discuss concepts such as positive and negative correlations, correlation coefficients, confounding variables, and causality.
Assignment: Benchmark - Correlation and Regression Project
Directions: Use the following information to complete the questions below. Use the following data points that have a linear relationship:
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Substance Abuse and Suicide: Percent of the Total U.S. Population
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X VARIABLE
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Y VARIABLE
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Year
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Substance Use
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Suicides
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1999
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6.82
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0.000105
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2000
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6.78
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0.000104
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2001
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7.00
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0.000107
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2002
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7.12
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0.00011
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2003
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7.09
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0.000108
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2004
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7.05
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0.00011
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2005
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7.17
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0.000109
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2006
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7.24
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0.00011
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2007
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7.28
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0.000113
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2008
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7.36
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0.000116
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2009
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7.80
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0.000118
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2010
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7.81
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0.000121
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2011
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7.88
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0.000123
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2012
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7.87
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0.000125
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2013
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8.07
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0.000126
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2014
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8.12
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0.00013
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2015
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8.06
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0.000133
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2016
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8.17
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0.000134
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2017
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8.18
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0.00014
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2018
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8.23
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0.000142
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In 500-750 words, address the following:
Identify the correlation coefficient for each of the possible pairings of variables. Describe the relationship in terms of strength (weak/strong) and direction (positive/negative).
Find a linear model of the relationship between the three variables of interest. Identify the predictor variables and the criterion variable.
Provide an output of the SPSS results and interpret the results using correct APA style. Be sure to include the following in your interpretation:
- Cause and effect concepts
- Independent/dependent variable relationships?
- Why is important to do random sampling?
- What is regression fallacy? How may it apply to the relationships discovered?\
Assignment: Review Questions
Describing Relationships: Correlation
Complete the following exercises from "Review Questions" located at the end of each chapter and put them into a Word document to submit to the instructor. Show all relevant work; use the equation editor in Microsoft Word when necessary.
6.9 Indicate whether the following generalizations suggest a positive or negative relationship. Also speculate about whether or not these generalizations reflect simple cause-effect relationships.
a. Preschool children who delay gratification (postponing eating one marshmallow to win two) subsequently receive higher teacher evaluations of adolescent competencies.
b. College students who take longer to finish a test perform more poorly on that test.
c. Heavy smokers have shorter life expectancies.
d. Infants who experience longer durations of breastfeeding score higher on IQ tests in later childhood.
7.8 Each of the following pairs represents the number of licensed drivers (X) and the number of cars (Y) for seven houses in my neighborhood:
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DRIVERS (X)
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CARS (Y)
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5
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4
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5
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3
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2
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2
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2
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2
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|
3
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2
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1
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1
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2
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2
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a. Construct a scatterplot to verify a lack of pronounced curvilinearity.
b. Determine the least squares equation for these data. (Remember, you will first have to calculate r, SSy, and SSx)
c. Determine the standard error of estimate, sy|x, given that n = 7.
d. Predict the number of cars for each of two new families with two and five drivers. C?