3. You work for SneauxCeauxne, the Cajun-inspired crushed-ice dessert company. You've collected data on monthly sales (S, number of snow-cones per month) and the price of your regular-size snow-cone (P, in dollars), as well as the daily average summer temperature in your most popular market (T, in degrees Fahrenheit). You estimate the following regression model: S = a + bP + cT. In your regressions, you usually look for a 10%-or-better level of confidence. a. What signs do you expect for a, b, and c