(a) The following model of number of dwellings approved for Victoria has been estimated using quarterly data. ragmeuingg = 1.437 + 1.3astog(popn,) 0. 0653mm, 0") (1.235) (0.231) (0.034) n=250, R2=o.s4 where dwelling stands for the number of new dwelling units and houses approved in Victoria, popn represents the total population of the state, and irate is the commercial banks' standard variable interest rate for housing loans. The standard errors are in parentheses. Interpret the estimated intercept and slope coefcients of the model. (3 marks} You have been asked by a car dealership located in Melbourne to model their monthly sales (SALES) as a function of how much is spent on advertising (ADV) and the average price of the cars (P) each month. You decide to estimate the following regression model using the historical database of the dealership over the period November 2007 - July 2021. SALES: = {30 + 31,491); + .8231ch + .341); + mc (I) Given the sample regression function belovwI interpret the effect of current month's advertising on current month's sales. Conduct a test of overall signicance of the model. The standard errors are in parentheses. ms: = 3253.57 + 1793541911, + 4250.35413V,_1 2010-621": (452.01) (932.11) (313.39) (133.27) n = 164 Ft2 = 0.84 (5 Marks) (ll) You also separately estimate the following exponential trend model for cars sales. Interpret how the series SALES is trending over time. lag (SAL'ESt) = 2.64 + 0.037: (2 Marks) (Ill) You further realise that sales may have been affected by the outbreak of ooronavirus since March 2020. How would you model and examine this impact? (2 Marks)