Need help with quiz

#1
10.The reason the t statistic has more variability than the Z statistic is that from sample to sample
a.the sample mean becomes smaller and the sample variance becomes larger.
b.the sample mean becomes larger and the sample variance becomes smaller.
c.neither the sample mean nor the sample variance remains constant.
d.both the sample mean and sample variance become larger.

11.The t distribution can be used with small samples for establishing confidence intervals for the population mean, provided that the population distribution
a.has a known variance.
b.is normally distributed.
c.is symmetric.
d.is continuous
:confused:
 
#3
Thanks for your help. I am really struggling in this class. I put "B" for #11.
This is only my first week in and I don't think I will make it 5 more. However, I am only this and 2 more classes away from my MBA. I may be reaching out again in the future. Thanks again for your help.