Basically degrees of freedom are related to sample size (n-1). If the df increases, it also stands that the sample size is increasing; the graph of the t-distribution will have skinnier tails, pushing the critical value towards the mean.
Hey there I just saw no one answered this problem and I know this is a little late but I will answer it anyways.
Answer: The answer to this problem would be points A and B
(6, 4, 4, 5, 1, 8, 10, 7, 8, 6, 6, 7, 5, 4, 6)
Lapatulllka [165]
<span>In a stem-and-leaf plot, </span><span>5| 4 means 54</span>