What is the mean corpuscular volume (MCV) calculated from a hematocrit (HCT) of 40% and a red blood cell (RBC) count of 5.0 x 10^12 /L?

To calculate the mean corpuscular volume (MCV), you can use the following formula:

[ \text{MCV} = \frac{\text{HCT} (\text{in percentage})}{\text{RBC count} (\text{in millions per microliter})} \times 10 ]

In this question, the hematocrit (HCT) is given as 40%, and the red blood cell (RBC) count is given as 5.0 x 10^12/L.

1. First, convert the RBC count from units of 10^12/L to millions per microliter. Since 1 x 10^12/L equals 1 million/microliter, the RBC count in millions per microliter is 5.0 million/microliter.

2. Now, substituting the values into the MCV formula:

[ \text{MCV} = \frac{40}{5} \times 10 = 8 \times 10 = 80 \text{ fL} ]

This calculation shows that the mean corpuscular volume is 80 fL, making this the correct answer. The MCV is a key parameter that helps