Answer:
The restocking level is 113 tins.
Step-by-step explanation:
Let the random variable <em>X</em> represents the restocking level.
The average demand during the reorder period and order lead time (13 days) is, <em>μ</em> = 91 tins.
The standard deviation of demand during this same 13- day period is, <em>σ</em> = 17 tins.
The service level that is desired is, 90%.
Compute the <em>z</em>-value for 90% desired service level as follows:

*Use a <em>z</em>-table for the value.
The expression representing the restocking level is:

Compute the restocking level for a 90% desired service level as follows:


Thus, the restocking level is 113 tins.