Brenda opened a pool and spa store in a lively shopping mall and finds business to be booming but she often stocks out of key items customers want. She decides to experiment with inventory control methods, such as using a continuous review $($fixed$-$order quantity$)$ and$/$or periodic review $($fixed$-$order period$)$ system. The $28-$ounce bottle of Super Algaecide $($SA$)$ is a high margin SKU, but it stocks out frequently. Ten SA bottles come in each box, and she orders boxes from a vendor $160$ miles away. Brenda is busy running the store and seldom has time to review store inventory status and order the right quantity at the right time. She collected the following data:

Demand $=4$ boxes per week

Order cost $=$$$\frac{30}{?}$ order

Item cost $=$$$\frac{60}{?}$ box

Inventory$-$holding cost $=25$ percent year

Store open $=48$ weeks$/$year

Lead$-$time $=4$ weeks

Std$.$ deviation in weekly demand $=7$

Service level $=90$ percent

a$.$ What is the economic order quantity $($EOQ$)$ rounded to the next highest number? Round to the nearest whole number. boxes

b$.$ What is the reorder point for SA with safety stock? Use Appendix A to determine $z-$value. Round $z-$value to two decimal places. Do not round intermediate calculations. Round your answer to one decimal place.

boxes

c$.$ What is the average number of orders per year using the EOQ? Do not round intermediate calculations. Round your answer to two decimal places.

orders$/$year