Marriage Ages

marr = read.csv("http://people.hsc.edu/faculty-staff/blins/StatsExamples/marriageAges.txt")
marrLM=lm(wife~husb,data=marr)
plot(marr$husb,marr$wife,xlab='Husband Age',ylab='Wife Age')
abline(marrLM)

Exercises

1. Find the correlation and the slope of the regression line. How are these two numbers different? What do they each mean?

2. Use the command confint() to find a 95% confidence interval for the slope.

Conditions for Inference

1. Linearity There is a linear relationship between the explanatory and response variables.

2. Independence The residuals are independent.

3. Normality The residuals are normally distributed.

4. Constant Variance The residuals all have the same standard deviation.

Are these conditions satisfied by the data above?