Ph produces many electronics products for the usa, europe, and the uk. the plugs required for each of these geographical areas are different, so originally ph had produced three different versions of each product. recently, they decided to create one version, and then ship these with three different plugs (i. e., of which two are redundant for the customer). the demands for a particular item for each market are normally distributed with the following parameters: usa – average of 10,000 with a standard deviation of 1,000, europe – average of 5,000 with a standard deviation of 1,000, and the uk – average of 5,000 with a standard deviation of 500. if ph wants a 90% service level, then how much should their safety stock be according to the new system with one version?