1. (a) H0: μ = 2, Ha: μ < 2 (b) Showing the administration your app when it does not save students time on average; not showing the admin your app when it does (c) ~0  (<0.0003) (d) yes
2. (a) 2, 1.22 (b) (-∞, 5.72) (c) (-∞, 6.17) (d) (0.734, 3.52)
3. (a) y = 2.95 + 0.0256 x (b) 0.0494 (c) 0.395 (d) positive; a little; probably just a coincidence
4. (a) binomial, 4 (b) normal, 4 (c) Poisson, 1 (d) gamma, 90 minutes
5. (a) 1/20 (b) 13.9, 46.1