a. Use Excel’s “Data Analysis” functions to determine the predictive model for the
above data. [8 marks]
b. Interpret the meaning of the slope coefficient, b1 and b2. [2 marks]
c. Explain why coefficient b0 would have no practical meaning in the context of this
problem. [1 marks]
d. Predict the train ticket sales for a month with a petrol price of $1.30/litre and 90% of
trains being on time. [4 marks]
e. Construct a 95% confidence interval estimate for the mean train ticket sales for a
month with a petrol price of $2.30/litre and 90%of the trains being on time.
[4 marks]
f. Determine whether there is a significant relationship between ticket sales and the two
independent variables at the 0.05 level of significance. [5 marks]
g. Interpret the meaning of the p-value. [2 marks]
h. Calculate the coefficient of multiple determination, R2 and interpret its meaning.
2
[4 marks]
i. Calculate the adjusted R2. [2 marks]
j. Perform a residual anlaysis on your results and determine the adequacy of this model.
[3 marks]
k. Plot the residuals against the weekdays(time). Is there evidence of a pattern in the
residuals? Explain. [4 marks]
l. Determine the Durbin-Watson statistics. [8 marks]
m. At the 0.05 level of significance, is there evidence of positive autocorrelation in the
residuals?