Question 1155554
mean is 175
standard deviation is 55.
that's the monthly demand.
the number of recorder necessary to keep on inventory to meet 85% of the demand is equal to 232 when rounded to the nearest integer.
here's the results from use of the statistical calculator that can be found at <a href = "http://davidmlane.com/hyperstat/z_table.html" target = "_blank">http://davidmlane.com/hyperstat/z_table.html</a>
<img src = "http://theo.x10hosting.com/2020/040901.jpg" alt="$$$" >