The monthly number of permits granted for building houses in a large city is seasonal (there tend to be more permits granted for construction during spring and summer months than during winter months). The following table shows the monthly seasonal indexes for building permits:
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
0.75 0.84 0.98 1.07 1.30 1.31 1.15 1.07 0.95 0.95 0.84 0.79
Using several years of permit data, beginning in August of 2001(i.e., t= 1 corresponds to August of 2001), an analyst reported that the trend line that describes the monthly permit data is of the form . Assuming Tt = 761 + 5t that a multiplicative model can be used to describe the building permit data, generate a forecast for the number of building permits that you expect will be granted in June of 2006.