If a sample has 20 observations and a 90 confidence estimate for ...

[fox]

If a sample has 20 observations and a 90 confidence estimate for  is needed, the appropriate t-score is:
 
  A) 2.120
  B) 1.746
  C) 2.131
  D) 1.729

Question 2

When a problem arises in counting the numbers of basic outcomes in the sample space and the event of interest to compute the probability of an event, it is helpful to use:
 
  A) sample spaces or complements.
  B) permutations or combinations.
  C) unions and intersections.
  D) subsets and events.

[patma1981]

Answer to Question 1

D

Answer to Question 2

B