1) Estimate the effect of advertising on the quantity demanded for your product using both a linear and a quadratic specification. Write down the equational forms. Which specification do you prefer? Will you be able to convince the investors that advertising your product is going to pay off? What are the limitations of your specification (omitted variables, correlation vs. causality)?

Demand			Advertising			Revenue
Quantity	Price		Advertising per day	Quantity per day		Quarter	Revenue
184	18.5		0	10		2012_01	232141.5
182	19		1	12		2012_02	233136.9
185	18.75		2	12		2012_03	296278.44
183	19		3	13		2012_04	292952.54
182	19.5		4	13		2013_01	298833.3
184	19.25		5	14		2013_02	288146.18
187	18.25		6	13		2013_03	347072.28
181	20		7	12		2013_04	353915.26
182	20		8	10		2014_01	384628.88
179	20.5		9	9		2014_02	399193.32
182	19.5		10	8		2014_03	357565.06
178	20.25		11	7		2014_04	422223.4
			12	6		2015_01	440682.54
			13	5		2015_02	468779.68
			14	4		2015_03	604109.84
			15	3		2015_04	516945.98
						2016_01	533110.96
						2016_02	471903.34
						2016_03	471652.12
						2016_04	524695.88
						2017_01	572908
						2017_02	548700.82
						2017_03	620968.44
						2017_04	609056.82
						2018_01	624209.02
						2018_02	659239.2