z Scores: Red Blood Cell Count Let x 5red blood cell (RBC) count in millions per cubic millimeter of whole blood. For healthy females, x has an approximately normal distribution with mean m 5 4.8 and standard deviation s 5 0.3 (based on information from Diagnostic Tests with Nursing Implications, edited by S. Loeb, Springhouse Press).

Convert each of the following x intervals to z intervals.

(a) 4.5 , x

(b) x , 4.2

(c) 4.0 , x , 5.5 Convert each of the following z intervals to x intervals.

(d) z , 21.44

(e) 1.28 , z

(f) 22.25 , z , 21.00

(g) Interpretation If a female had an RBC count of 5.9 or higher, would that be considered unusually high? Explain, using z values and Figure 6-15.

AppendixLO1