In: Statistics and Probability
A random sample of eight auto drivers insured with a
company and having similar auto insurance policies
was selected. The following table lists their driving experience
(in years) and the monthly auto insurance
premium (in dollars).
Driving Experience(years) 5 2 12 9 15 6 25 16
Monthly Premium(dollars) 64 87 50 71 44 56 42 60
Answer the following questions.
(a) Does the insurance premium depend on driving experience or does
the driving experience depend on
insurance premium? Do you expect a positive or a negative
relationship between these two variables?
Part of the Minitab Computer output is the following.
The regression equation is
premium = 76.7 - 1.55 years
Predictor Coef Stdev t-ratio p
Constant 76.660 6.961 11.01 0.000
years -1.5476 0.5270 -2.94 0.026
s = 10.32 R-sq = 59.0%
(b) Plot the scatter diagram and the regression line.
(c) What does the intercept, β0, mean in the context of this
problem?
(d) Construct a 95% confidence interval for the intercept,
β0.
(e) What does the slope, β1, mean in the context of the problem?
What is the implication for the relationship
of the premium and the years of driving experience when β1 = 0?