Question 1152581
The mean of a normal probability distribution is 615; the standard deviation is 17.
  
(a)	About 68% of the observations lie between what two values?
<pre>Between 615-17 and 615+17 which is between 598 and 632</pre>
B) About 95% of the observations lie between what two values?
<pre>Between 615-2(17) and 615+2(17) which is between 581 and 649</pre>
c) 	Practically all of the observations lie between what two values?
<pre>Between 615-3(17) and 615+3(17) which is between 564 and 666

Edwin</pre>