In the article “Prevalence and Predictability of Low-yield Inpatient Laboratory Diagnostic Tests” published in JAMA Network Open (Xu, 2019), the authors report the results of a study on laboratory tests detecting normal magnesium levels in blood.

The reported estimated prevalence was 0.26, the sensitivity of the test was 0.86, and the specificity of the test was 0.47. Determine

(a) the estimated positive predictive value for this test.

(b) the estimated negative predictive value for this test.