The narrower the confidence interval, the more precise it is. ...

[APUS57]

The narrower the confidence interval, the more precise it is. With this in mind, which combination of factors will produce the most precise estimate of the difference between two population means?
 
  a. Two samples of n = 20 and 80 confidence
  b. Two samples of n = 20 and 90 confidence
  c. Two samples of n = 50 and 80 confidence
  d. Two samples of n = 50 and 90 confidence

Question 2

An independent-measures study comparing two treatment conditions with n = 6 in each sample produces t = 4.00 . What is the value of r2for this study?
 
  a. 4/26 c. 16/26
  b. 4/28 d. 16/28

[trampas]

Answer to Question 1

C

Answer to Question 2

C