STP Data Analysis 2

Question 1

In a clinical laboratory study, a Levey-Jennings chart is used primarily to:

Accepted Answer

Monitor quality control over time

Answer

Levey-Jennings charts plot QC results over time to detect trends, shifts, and random errors in analytical processes.

Question 2

Which statistical test is most appropriate for comparing the means of three or more independent groups?

Accepted Answer

One-way ANOVA

Answer

One-way ANOVA compares means across three or more independent groups simultaneously, controlling the type I error rate.

Question 3

A dataset has a mean of 50 and a standard deviation of 5. What is the coefficient of variation (CV)?

Accepted Answer

10%

Answer

CV = (SD/mean) × 100 = (5/50) × 100 = 10%, expressing variability relative to the mean.

Question 4

When a regression line has a slope of zero, this indicates:

Accepted Answer

No linear relationship between variables

Answer

A slope of zero means changes in the independent variable are not associated with changes in the dependent variable.

Question 5

In Bland-Altman analysis, the limits of agreement are calculated as:

Accepted Answer

Mean difference ± 1.96 SD

Answer

Limits of agreement are the mean difference ± 1.96 SD, capturing approximately 95% of differences between two methods.

(STP) Scientist Training Programme Practice Test