Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 46 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that = 7.00 ml/kg for the distribution of blood plasma.
(a) Find a 80% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Use 2 decimal places.)
lower limit=
upper limit=
moe =

(b) What conditions are necessary for your calculations? (Select all that apply.)
the distribution of weights is normal
is known
n is large
is unknown
the distribution of weights is uniform

(c) Give a brief interpretation of your results in the context of this problem.
The probability that this interval contains the true average blood plasma volume in male firefighters is 0.80.
20% of the intervals created using this method will contain the true average blood plasma volume in male firefighters.
The probability that this interval contains the true average blood plasma volume in male firefighters is 0.20.
80% of the intervals created using this method will contain the true average blood plasma volume in male firefighters.

(d) Find the sample size necessary for a 80% confidence level with maximal/marginal error of estimate E = 2.00 for the mean plasma volume in male firefighters.

What does just-in-time inventory management have to do with the Carle Heart Center in Urbana, Illinois? The Carle Heart Center is one of the most sophisticated cardiac-care facilities in the Midwest. Integral to the success of Carle are three separate cardiac catheterization labs that are miles apart. These cath labs have pioneered techniques and technologies ranging from intravascular brachytherapy to digital cardiovascular imaging. The latest addition to this forward-thinking heart care center is a department-wide networking system from General Electric Medical Systems called CardioLink. Part of the CardioLink is a just-in-time inventory system. According to Carle’s Cath Lab Manager Alan Kettelkamp, “Department- wide access to our Lab Management Tools not only eliminates the need for maintaining individual inventory systems for each lab, it also allows us to apply just-in-time techniques. We simply push a button to see which supplies are below our par levels, by vendor. Our inventory specialists can then print out replenishment orders and fax them out for next-day shipment. We’re even able to enter the replenishments into our system with a bar-code reader. This system has perfected our order-management process, and it has allowed us to reduce our total inventory significantly.”
1. What are the benefits of the just-in-time inventory management system to Carle’s Cath Lab?
2. What do you think would be a “safe” inventory level for Carle’s Cath Lab? Is it 3 or 4 days as with Dell, or is it longer?
3. In what other critical service areas besides health care would a just- in-time inventory management system prove beneficial?