Question 867588
First you need the standard z-score



z = (x - mu)/sigma



z = (3.2 - 3.9)/0.3



z = -2.33333333333333



z = -2.33 <font color="blue">round to 2 decimal places</font>



Now we use a table like <a href="http://www.deeannef.com/apstats/normal/normtbl2.gif">this one here</a> to find the area under the standard normal distribution curve that is to the left of z = -2.33



According to the table, the area is roughly 0.0099 (look in the row that starts with -2.3 and then look in the column that starts with 0.03, where they intersect is at the cell with the number 0.0099 in it)



So the approximate answer is <font color="red">0.0099</font>



If you need a more accurate answer, use a calculator that can compute normal cdfs