Question 251238
mean is 50.
Standard Deviation is 10.


Top 10% get an A.
Bottom 10% get an F.


Based on normal distribution, you can use the Z-Table Calculator to find the percentages of the population that fall under each category.


Any score below 37.1845 will get an F.


Any score above 62.8155 will get an A.


Select the following link to access the z-table calculator.


<a href = "http://davidmlane.com/hyperstat/z_table.html" target = "_blank">http://davidmlane.com/hyperstat/z_table.html</a>


you select the bottom graph.
enter a mean of 50
enter a standard deviation of 10
enter a shaded area of .1
select below to get the bottom 10%
select above to get the top 10%


the graph will show you the area you picked.