Mary is using a one-sample t-test on the following group: Subject #15: 7.5 hours Subject #27: 6 hours Subject #48: 7 hours Subject #80:6.5 hours Subject #91: 7.5 hours Subject #82: 8 hours Subject #23:5.5 hours Select the two TRUE statements. a.) The t-distribution that Mary uses has skinnier tails than a standard distribution. b.) The value for the degrees of freedom for Mary's sample population is six. c.) The t-distribution that Mary uses is taller than a standard distribution. d.) Mary would use the population standard deviation to calculate a t- distribution. e.) Mary would use the sample standard deviation to calculate a t-statistic. Teems need to be seleted