Standard normal table:

Only part c needs an answer

Nationwide Auto Parts uses a periodic review inventory control system for one of its stock items. The review interval is 12 weeks, and the lead time for receiving the materials ordered from its wholesaler is 4 weeks. Weekly demand is normally distributed, with a mean of 250 units and a standard deviation of 50 units. Refer to the standard normal table for z-values. The table below shows the total area under the normal curve for a point that is Z standard deviations to the right of the mean. z 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.5000 0.5040 0.50800.5120 0.51600.5199 0.5239 0.5279 0.5319 0.5359 0.5398 0.5438 0.5478 0.5517 0.5557 0.5596 0.5636 0.5875 0.5714 0.5754 0.5793 0.58320.5871 0.59 10 0.5948 0.5987 0.6026 0.6064 0.8103 0.6141 0.6179 0.6217 0.6255 0.6293 0.6331 0.6368 0.6406 0.6443 0.8480 0.6517 0.65540.6501 0.6828 0.68640.6700 0.6736 0.6772 0.6808 0.8844 0.6879 0.6915 0.6950 0.6985 0.7019 0.7054 0.7088 0.7123 0.7157 0.7190 0.7224 0.7258 0.7291 0.7324 0.7357 0.7389 0.7422 0.7454 0.7486 0.75180.7549 0.7580 0.7612 0.76420.76730.77040.77340.7764 0.77940.7823 0.7852 0.7881 0.7910 0.7939 0.7967 0.7996 0.8023 0.8051 0.8079 0.8106 0.8133 0.8159 0.8186 0.8212 0.8238 0.8264 0.8289 0.8315 0.8340 0.8365 0.8389 0.8413 0.8438 0.8461 0.8485 0.8508 0.8531 0.85540.85770.8599 0.8621 0.8643 0.8665 0.8686 0.8708 0.8729 0.8749 0.8770 0.8790 0.8810 0.8830 0.8849 0.8869 0.8888 | 0.89070.8925 0.8944 0.8982 0.89800.8997 0.9015 0.9032 0.9049 0.9066 0.9082 0.9099 0.9115 0.9131 0.9147 0.91620.9177 0.9192 0.9207 0.9222 0.9236 0.9251 0.9205 0.9279 0.9292 0.9306 0.9319 0.9332 0.9345 0.9357 0.9370 0.93820.9394 0.9406 0.9418 0.9430 0.9441 0.9452 0.9463 0.9474 0.9485 0.9495 0.9505 0.9515 0.9525 0.9535 0.9545 0.9554 0.9564 0.9573 0.9582 0.9591 0.9599 0.9808 0.9816 0.9625 0.9633 0.9641 0.9649 0.9656 0.98640.9671 0.9678 0.9886 0.9893 0.9700 0.9706 0.9713 0.9719 0.9726 0.9732 0.9738 0.9744 0.9750 0.9756 0.9762 0.9767 0.97730.9778 0.97830.9788 0.9793 0.9798 0.98030.9808 0.98120.9817 0.9821 0.9826 0.9830 0.9834 0.9838 0.98420.9846 0.9850 0.9854 0.9857 0.9861 0.9865 0.9868 0.9871 0.98750.9878 0.9881 0.9884 0.9887 0.9890 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 0.9893 0.9896 0.9898 0.9901 0.99040.9906 0.9909 0.9911 0.99130.9916 0.9918 0.9920 0.9922 0.9925 0.99270.9929 0.9931 0.99320.99340.9936 0.9938 0.9940 0.9941 0.99430.9945 0.9946 0.9948 0.99490.9951 0.9952 0.9953 0.9955 0.9956 0.9957 0.99590.9900 0.9981 0.9962 0.99630.9984 0.9965 0.9988 0.99670.9968 0.9969 0.9970 0.99710.9972 0.9973 0.9974 0.99740.9975 0.9978 0.9977 0.9977 0.9978 0.9979 0.99800.99800.9981 0.9981 0.99820.9983 0.9983 0.9984 0.99840.9985 0.9985 0.9986 0.9986 0.99870.9987 0.9987 0.9988 0.9988 0.9989 0.9989 0.9989 0.9990 0.9990 0.9990 0.9991 0.9991 0.9991 0.9992 0.9992 0.9992 0.9992 0.9993 0.9993 0.9993 0.9993 0.99940.99940.9994 0.9994 0.99940.9995 0.9995 0.9995 0.9995 0.9995 0.9995 0.9995 0.9996 0.9998 0.9996 0.9996 0.9996 0.9997 a. What is the average and the standard deviation of demand during the protection interval? The average demand during the protection interval is 4000 units. (Enter your response as an integer.) The standard deviation of demand is 200 units. (Enter your response rounded to two decimal places.) b. If the firm desires 99 percent stockout protection, the target inventory level is 4466 units. (Enter your response rounded to the nearest whole number.) C. If 375 units were in stock at the time of a periodic review. I units should be ordered. (Enter your response rounded to the nearest whole number.)