Answer
(a) $H_0:~µ=3173$ versus $H_1:~µ\lt3173$
(b) To conclude that the mean outstanding credit-card debt of college undergraduates has decreased when, in fact, this amount remains equal to $\$3173$.
(c) If we do not conclude that the mean outstanding credit-card debt of college undergraduates has decreased when, in fact it has happened.
(d) There is not enough evidence to conclude that the mean outstanding credit-card debt of college undergraduates has decreased since 2010.
(e) there is enough evidence to conclude that the mean outstanding credit-card debt of college undergraduates has decreased since 2010.
Work Step by Step
Given above.
