TU Wien:Statistik und Wahrscheinlichkeitstheorie UE (Bura)/Übungen 2019W/4.1

Human resource testing

Some human resource deprtments administer standard IQ tests to all employees. The Stanford-Binet test scores are well modeled by a Normal model with expectation 100 and standard deviation 16.

(a) If the applicant pool is well modeled by this distribution, a randomly selected applicant would have what probability of scoring in the region between 84 and 116?

(b) For the IQ test administered by human resources, what cutoff value would separate the middle 95%?

Lösungsvorschlag von Gittenburg

--Gittenburg 17:39, 3. Nov. 2019 (CET)

(a)

> pnorm(116, 100, 16) - pnorm(84, 100, 16)
[1] 0.6826895

(b)

> qnorm(0.95, 100, 16)
[1] 126.3177

edit: Hier wird das 95% Quantil angezeigt. Die Frage ist aber, welcher Wert die mittlerent 95% abtrennt, also die Range 2.5% - 97.5%, bzw (-1.96, +1.96). In IQ - Punkten wäre dieser Wert dann +/- 31.36