A store wants to predict quarterly sales. The owner has collected 3 years of sales data and wants your help in analyzing the data using the multiplicative seasonal effects model.

	A	B	C	D	E	F	G	H	I	J
1			Time	Actual		Seasonal
2	Year	Qtr	Period	Sales	Level	Factor	Forecast
3	1	1	1	368	462.50	0.796			alpha	0.332167
4		2	2	168	462.50	0.363			beta	1
5		3	3	530	462.50	1.146
6		4	4	784	462.50	1.695
7	2	1	5	770	630.32	1.222	368.00
8		2	6	354	744.66	0.475	228.96
9		3	7	1012	790.65	1.280	853.34
10		4	8	1244	771.79	1.612	1340.26
11	3	1	9	1326	875.98	1.514	942.82
12		2	10	986	1273.96	0.774	416.43
13		3	11	1624	1272.25	1.276	1630.62
14		4	12	2090	1280.35	1.632	2050.66
15
16							85564.040

Refer to Exhibit 11.5. What formula should be entered in cell E3 to compute the base level when using the multiplicative seasonal effects method?

a. =AVERAGE($E$3:$E$6)

b. =AVERAGE($D$3:$D$6)

c. =AVERAGE(D3, D7, D11)

d. =AVERAGE(E3, E7, E11)