Another seasonal model. Use the following model to forecast quarterly profits of a company (where time is rescaled to begin at zero and Q2, Q3, and Q4 are dummy variables for the indicated quarters), and answer the following questions.

yn = 9.8 + 5.4 t - 4.0 Q2 + 3.4 Q3 - 5.4 Q4

a) What are the profits for the second quarter of the time series?

b) Which quarter will, on average, record the lowest level of profits over the time frame of the series?

c) Which quarter will, on average, record the highest level of profits over the time frame of the series?

d) Interpret the coefficient of the dummy variable named Q3.