: <p>

95% of the incomes of members of the population are between X
- $10,000 and X + $10,000.  <p>

95% of the incomes of members of the population are between
$19,000 and $21,000.  <p>

In 95% of all possible samples X is between $19,000 and
$21,000.  <p>

In 95% of all possible samples the sample average will be
between X - $1000 and X + $1000.  <p>

How many of the above statements are certainly true? <p>

a. one 
    b. two
 	
 c. three 
 	
 d. four 
    e. none