Question 557798
For a normally distributed population, mean of 6.5 and standard
deviation of 4, compute: 

a.	The probability of picking one item from the population and having it fall between 6.5 and 14.75
<pre>
z-score for left endpoint 6.5 is = {{{(x-mu)/sigma}}} = {{{(6.5-6.5)/4}}} = 0

(1) if your z-table reads from the middle, look up z=0, get 0 
(2) if your z-table reads from the left, look up z=0, get 0.5

z-score for right endpoint 14.75 is {{{(x-mu)/sigma}}} = {{{(14.75-6.5)/4}}} = 2.0625, round to 2.06

(1) if your z-table reads from the middle, look up 2.06, get .4803 
(2) if your z-table reads from the left, look up 2.06, get .9803


(1) if your z-table reads from the middle, subtract .4803-0 = .4803  
(2) if your z-table reads from the left, subtract .9803-.5 = .4803

Answer: .4803

Edwin</pre>