Problem 1:
(a) y = 3.01 + 0.013x
(b) 0.0197
(c) 0.711
(d) t score is 0.246 --> you cannot conclude that your app impacts GPA
   
Problem 2:
(a) H0: μ = 3.0  Ha: μ > 3.0
(b) t score is 1 --> you cannot reject 
(c) 3.213
(d) 0.871

Problem 3: sample mean is 20, standard deviation 12.7
(a)  (-44.7, 84.7)
(b)  (-18.8, 58.8)
(c)  (4.17, 35.8)
(d)  (7.64, 36.6)

Problem 4:
(a) 0.837
(b) 2.91, 0.35 <--- the investors stop you after 3 jokes, so that is the max you will tell
(c) exp(-1) = 0.368
(d) 3 minutes, sqrt(3) minutes

Problem 5:
(a) 0.607, 0.795
(b) $607, $795
(c) $607, $688
(d) Accept any answer that is logically correct: e.g. (c) is better because there the mean is the same but the risk is less; or (b) is better because there is a higher probability of getting more money than we start with.

Problem 6:
(a) 10%
(b) No, 0.4 * 0.2 ≠ 0.1
(c) 25%