To go from the equation in the previous problem to the equation ...

[rmenurse]

To go from the equation in the previous problem to the equation for t we must
 
  a. substitute sample means for population means.
  b. substitute sample variances for population variances.
  c. substitute sample standard deviations for population variances.
  d. draw very large samples.

Question 2

The t statistic differs from z in that
 
  a. it applies to variances.
  b. it is used when population variances are not known.
  c. it involves an assumption of normality.
  d. and b) but not c).

[izzat]

Answer to Question 1

B

Answer to Question 2

B