What does the CV calculated in Question 2 describe about the ...

[hbsimmons88]

What does the CV calculated in Question 2 describe about the white cell counts?
 
  a. Accuracy
  b. Reliability
  c. Proper calibration
  d. Precision

Question 2

A patient's white blood cells (WBCs) are counted on an automated cell counter 10 times. The mean white count is 8000/mL, and the standard deviation (SD) is 300. What is the coefficient of variation (CV)?
 
  a. 0.04
  b. 2.6
  c. 3.8
  d. 26

[amy.lauersdorf90]

Answer to Question 1

ANS: D
The CV is a measure of precision or how well a result can be reproduced. It allows comparisons of assays with different means and is a unitless number, although usually expressed as a percentage. Accuracy is how close a result is to the true value; proper calibration is required to obtain accuracy. Reliability is how well a method holds both accuracy and precision over time.

Answer to Question 2

ANS: C
 CV = (SD/mean)  100 = (300/8000)  100 = 3.8