The following output from MINITAB presents the results of a hypothesis test for a population mean $\mu$.
Test of mu $= 45$ vs. not $= 45$
$\begin{array}{lrrccrl}
\mathrm{N} & \text { Mean } & \text { StDev } & \text { SE Mean } & 95 \% \mathrm{CI} & \mathrm{T} & \mathrm{P} \
57 & 41.69 & 11.961865 & 1.584388 & (38.516105,44.863895) & -2.089135 & 0.0412
\end{array}$

How many degrees of freedom are there?
A) 58
B) 45
C) 56
D) 57

Question

The following output from MINITAB presents the results of a hypothesis test for a population mean $\mu$.
Test of mu $= 45$ vs. not $= 45$
$\begin{array}{lrrccrl}
\mathrm{N} & \text { Mean } & \text { StDev } & \text { SE Mean } & 95 \% \mathrm{CI} & \mathrm{T} & \mathrm{P} \
57 & 41.69 & 11.961865 & 1.584388 & (38.516105,44.863895) & -2.089135 & 0.0412
\end{array}$

How many degrees of freedom are there?
A) 58
B) 45
C) 56
D) 57

Quizplus · Accepted Answer

The degrees of freedom for a one-sample t-test are calculated as $N - 1$, where $N$ is the sample size. Here, $N = 57$, so the degrees of freedom are $57 - 1 = 56$.

The Following Output from MINITAB Presents the Results of a Hypothesis