*2.3 The estimated demand function for ice cream at a popular beach on a summer day is given by Q = 200 - 4.5p, where p is measured in euros. What is the predicted quantity if p = €2.00? If the actual quantity demanded is 195, what is the residual? Suggest at least two unobserved variables incorporated in the random error. (Hint: See Q&A 3.3.)