For a t distribution with 16 degrees of freedom, find the area, or probability, in each region.

a. To the right of 2.120. (Use 3 decimals.)

b. To the left of 1.337. (Use 2 decimals.)    

c, To the left of -1.746. (Use 2 decimals.) 

d. To the right of 2.583. (Use 2 decimals.) 

e. Between -2.120 and 2.120. (Use 2 decimals.) 

f. Between -1.746 and 1.746. (Use 2 decimals.) 

2. A survey of 611 office workers investigated telephone answering practices, including how often each office worker was able to answer incoming telephone calls and how often incoming telephone calls went directly to voice mail (USA Today, April 21, 2002). A total of 281 office workers indicated that they never need voice mail and are able to take every telephone call.

a. What is the point estimate of the proportion of the population of office workers who are able to take every telephone call (to 2 decimals)? 

b. At 90% confidence, what is the margin of error (to 4 decimals)? 

c. What is the 90% confidence interval for the proportion of the population of office workers who are able to take every telephone call (to 4 decimals)?