Which of the following is not true about the Student's t ...

[j.rubin]

Which of the following is not true about the Student's t distribution?
 
  A) It is bell shaped and symmetrical.
  B) It has more area in the tails and less in the center than does the normal distribution.
  C) It is used to construct confidence intervals for the population mean when the population standard deviation is known.
  D) As the number of degrees of freedom increases, the t distribution approaches the normal distribution.

Question 2

The amount of time necessary for assembly line workers to complete a product is a normal variable with a mean of 15 minutes and a standard deviation of 2 minutes. The probability is ________ that a product is assembled in between 14 and 16 minutes.
 
  Fill in the blank(s) with correct word

[Edwyer]

Answer to Question 1

C

Answer to Question 2

0.3829 using Excel or 0.3830