Research & Design (R&D) has determined the following: The weight of the overshoes must be at least 60% of the weight of the “client” in freshwater applications. For example, if the client weighs 100 pounds, the overshoes must weigh at least 60 pounds to make them As sink. As saltwater has greater buoyancy, the overshoes must be at least 80% of the weight of the “client” to ensure that the “client” always sinks to the bottom (e.g., a 100-pound client needs an overshoe that weighs a minimum of 80 pounds). While we want a one-size-fits-all product, we still want to make them as light as possible to save materials. Therefore, we must determine the lightest overshoe that will make the heaviest conceivable client sink. We must also factor in whether the application is salt or fresh water. Moreover, working with the customer, Marketing has taken a sample of 48 clients’ weights and recorded the values below. The weights of saltwater clients must be considered separately from freshwater ones. As the clients must always sink, our sample of forty-eight clients cannot possibly encompass the weights of every realistically conceivable client. Therefore, we must use statistics. For our purposes, we will use the sample data to estimate the weight of every realistically conceivable client. We need to be 99.99% confident (i.e., 4 standard deviations) in our client weight projections.
Expert Answer
Fresh | Salt | |||
R | Ratio | 0.6 | 0.8 | |
m | Mean | 198.17 | 222.21 | |
s | Std Dev | 65.71 | 28.85 | |
Mw | Max Wt | 351 | 288 | |
mw | Min Wt | 125 | 159 | |
T | Target | 99.99% | 99.99% | |
NORMINV(Target,m,s) | O | So Max overshoe (m+s*z) | 442.5465733 | 329.5036 |
O*R | Final weight | So percentage weight | 265.527944 | 263.6029 |
So the required weight is max of 265.53 and 263.60
Hence for 99.99 coverage the wt should be 265.53.