Outcomes and the Type I and Type II Errors · Exercise 16

Previously, an organization reported that teenagers spent 4.5 hours per week, on average, on the phone. The organization thinks that, currently, the mean is higher. Fifteen randomly chosen teenagers were asked how many hours per week they spend on the phone. The sample mean was 4.75 hours with a sample standard deviation of 2.0. Conduct a hypothesis test, the Type I error is:

(a) to conclude that the current mean hours per week is higher than 4.5, when in fact, it is higher
(b) to conclude that the current mean hours per week is higher than 4.5, when in fact, it is the same
(c) to conclude that the mean hours per week currently is 4.5, when in fact, it is higher
(d) to conclude that the mean hours per week currently is no higher than 4.5, when in fact, it is not higher

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Introductory Statistics 2e · §9.2 Outcomes and the Type I and Type II Errors · Exercise 16