The chair of the operations management department at Quality University wants to construct a p$-$chart for determining whether the four faculty teaching the basic P$/$OM course are in control with regard to the number of students who fail the course. Accordingly, he sampled $100$ final grades from last year for each instructor, with the following results:

Instructor Number of Failures

Prof. A $13$

Prof. B $0$

Prof. C $11$

Prof. D $16$

Using $\mathrm{.}95$ control limits $(5$ percent risk of Type I error$),$ which instructor$($s$),$ if any, should he conclude is $($are$)$ out of control?

Multiple Choice

all

Prof. D

Prof. B

none

both Prof. B and Prof. D