Chapter 3

A Gaussian distribution is usually a. Bell shaped b. Rectangular c. Uniform d. Skewed

The following chloride (mmol/L) results were obtained using a new analyzer: $$\begin{array}{rrrrrr}106 & 111 & 104 & 106 & 112 & 110 \\ 115 & 127 & 83 & 110 & 108 & 109 \\ 83 & 119 & 105 & 106 & 108 & 114 \\ 120 & 100 & 107 & 110 & 109 & 102\end{array}$$ What is the mean? a. 108 b. 105 c. 109 d. 107

The following chloride \((\mathrm{mmol} / \mathrm{L})\) results were obtained using a new analyzer: $$\begin{array}{rrrrrr} 106 & 111 & 104 & 106 & 112 & 110 \\ 115 & 127 & 83 & 110 & 108 & 109 \\ 83 & 119 & 105 & 106 & 108 & 114 \\ 120 & 100 & 107 & 110 & 109 & 102\end{array}$$ What is the median? a. \(108.5\) b. 105 c. 112 d. 107

For a data value set that is Gaussian distributed, what is the likelihood (\%) that a data point will be within \(\pm 1\) SD from the mean? a. \(68 \%\) b. \(99 \%\) c. \(95 \%\) d. \(100 \%\)

If two methods agree perfectly in a method comparison study, the slope equals and the \(y\) -intercept equals. a. \(1.0,0.0\) b. \(0.0,1.0\) c. \(1.0,1.0\) d. \(0.0,0.0\) e. \(0.5,0.5\)

Systematic error can best be described as consisting of a. Constant and proportional error b. Constant error c. Proportional error d. Random error e. Syntax error

Examples of typical reference interval data distribution plots include all of the following except a. \(\mathrm{ROC}\) b. Nonparametric c. Parametric d. Bimodal

Diagnostic specificity is the a. Ability of a test to correctly identify the absence of a given disease or condition b. Chance an individual does not have a given disease or condition if the test is within the reference interval c. Chance of an individual having a given disease or condition if the test is abnormal d. Ability of a test to detect a given disease or condition

To evaluate a moderately complex laboratory test, all of the following must be done except: a. Analytical sensitivity and specificity b. Verification of the reference interval c. Accuracy and precision d. Reportable range

An ROC includes all of the following except: a. Perfect test \(=\) an area under the curve \(<1.0\) b. Equals receiver operator characteristic c. Plots sensitivity and 1 - specificity d. Can be used to compare two different tests

Allowable analytical error is a. A combination of random and systematic error b. Best if it is greater than the total error c. Used only for research and initial evaluation studies