The z test for independent groups is seldom used because ...

[Redwolflake15]

The z test for independent groups is seldom used because _________.
 
  a. it lacks sensitivity
  b. it is too complicated
  c. we seldom know the population variances
  d. the sampling distribution of z under H0 is unknown

Question 2

Having just made what you feel is to be a Type II error, using an independent groups design and a t test analysis, which of the following might you do in the next experiment to reduce the probability of a Type II error?
 
  a. increase N
  b. change to a correlated groups design
  c. try to reduce the variance by better experimental control
  d. all of these

[heinisk01]

Answer to Question 1

C

Answer to Question 2

D

[Redwolflake15]

Excellent

[rleezy04]

Thanks for the timely response, appreciate it