# Question about calculation involving inequalities

• Oct 18th 2010, 11:37 AM
Stranger
I work in a lab and we often have to do iron profiles on patients. The total saturation is a calculated value produced from the following formula. Total Saturation(TSat) = Iron(Fe)/(Transferrin(Trans) * 0.25) * 17.5 We often get an Fe or a Trans result that is less than the cutoff value. Since the Fe is in the numerator I know it is directly proportional to the TSat and the TSat will be less than if the Fe is less than. I know as well that since the Trans is in the denominator it is inversely proportional to the Tsat and if the Trans is less than the Tsat will be greater than. The question I have is, what if BOTH the Fe and the Trans are less than the cutoff? How does one handle that? Do the less than and greater than signs cancel each other out?

Thanks for any elightenment you can give me.
• Oct 18th 2010, 11:46 AM
NOX Andrew
I'm not sure I understand the question. Are you inquiring about the behavior of TSat when both Fe and Trans are less than a cutoff value? If so, then you cannot make any assumptions about the behavior of TSat (unlike when only one was less than a cutoff value).
• Oct 19th 2010, 11:08 AM
Stranger
You are correct. That is indeed what I am asking. So there is no definitive answer for this?