Nationwide auto parts uses a periodic review inventory control system for one of its stock items. the review interval is six weeks, and the lead time for receiving the materials ordered from its wholesaler is three weeks. weekly demand is normally distributed, with mean of 100 units and a standard deviation 20 units. a) what are the average and the standard deviation of demand during the protection interval? b) what should be the target inventory level if the firm desires 97.5 percent stock-out protection? c) if 350 units were in stock at the time of a certain periodic review, how many units should be ordered?

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step-by-step explanation:

the graph in the attached figure

step-by-step explanation:

we have

using a graphing tool

the graph in the attached figure

the roots are ( x-intercepts) x=-0.5,x=1,x=3

the y-intercept is the point (0,3)

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;