Purchase Solution

Multiple Regression and Non Parametric Methods

Not what you're looking for?

Ask Custom Question

See Attached File

Attachments
Purchase this Solution

Solution Summary

A few good quality statistics questions on linear regression are solved using R.

Solution Preview

14.20
data stored in a file: 1420_data.txt as follows:
County MedianIncome MedianAge Coastal
A 48157 57.7 1
B 48568 60.7 1
C 46816 47.9 1
D 34876 38.4 0
E 35478 42.8 0
F 34465 35.4 0
G 35026 39.5 0
H 38599 65.6 0
J 33315 27.0 0

Using R:
a.
Is there a linear relationship between the median income and median age?

d1420<-read.table("1420_data.txt", header=TRUE)
> colnames(d1420) = c("County", "MedianIncome", "MedianAge", "Coastal")
> attach(d1420)
The following object(s) are masked from 'd1420 (position 3)':

Coastal, County, MedianAge, MedianIncome
> cor.test(MedianIncome, MedianAge)

Pearson's product-moment correlation

data: MedianIncome and MedianAge
t = 2.7561, df = 7, p-value = 0.02825
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
0.1099740 0.9367364
sample estimates:
cor
0.7214069

Conclusion: Yes there is correlation between Median Income and Median Age.

b.
Which variable is the "dependent" variable?

Median Income is Median Income.

c.
Use statistical software to determine the regression equation. Interpret the value of the slope in a simple regression equation.

> lm(MedianIncome~ MedianAge)

Call:
lm(formula = MedianIncome ~ MedianAge)

Coefficients:
(Intercept) MedianAge
22804.7 361.6

i.e.,

MedianIncome = 361.6*MedianAge + 22804.7

d.
Include the aspect that the county is "coastal" or not in a multiple linear regression analysis using a "dummy" variable. Does it appear to be a significant influence on incomes?

> lmIncAgeCoast = lm(formula = MedianIncome ~ MedianAge + Coastal)
> summary(lmIncAgeCoast)

Call:
lm(formula = MedianIncome ~ MedianAge + Coastal)

Residuals:
Min 1Q Median 3Q Max
-0.27723 -0.14934 0.01199 0.06174 ...

Solution provided by:
Education
  • BEng, Allahabad University, India
  • MSc , Pune University, India
  • PhD (IP), Pune University, India
Recent Feedback
  • " In question 2, you incorrectly add in the $3.00 dividend that was just paid to determine the value of the stock price using the dividend discount model. In question 4 response, it should have also been recognized that dividend discount models are not useful if any of the parameters used in the model are inaccurate. "
  • "feedback: fail to recognize the operating cash flow will not begin until the end of year 3."
  • "Answer was correct"
  • "Great thanks"
  • "Perfect solution..thank you"
Purchase this Solution


Free BrainMass Quizzes
Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.