Determine key characteristics of a t-distribution.

Miriam is using a one-sample t-test on the following group:

Subject #15: 6.5 hours

Subject #27: 5 hours

Subject #48: 6 hours

Subject #80: 7.5 hours

Subject #91: 5.5 hours

Select the two TRUE statements.

• a.)The value for the degrees of freedom for Miriam's sample population is four.
• b.)The value for the degrees of freedom for Miriam's sample population is five.
• c.)The t-distribution that Miriam uses is taller and has thinner tails than a normal distribution.
• d.)Miriam needs to use a t-test when the standard deviation is known.
• e.)The t-distribution that Miriam uses is shorter and has thicker tails than a normal distribution.