[R] Solving a normal distribution pnorm for q

[Jeff Newmiller]

?pnorm ... carefully...
---------------------------------------------------------------------------
Jeff Newmiller                        The     .....       .....  Go Live...
DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live Go...
                                      Live:   OO#.. Dead: OO#..  Playing
Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
/Software/Embedded Controllers)               .OO#.       .OO#.  rocks...1k
--------------------------------------------------------------------------- 
Sent from my phone. Please excuse my brevity.

Johannes Radinger <johannesradinger at gmail.com> wrote:
>Hi,
>
>
>
>I found follwowing example of pnorm here:
>
>http://www.r-tutor.com/elementary-statistics/probability-distributions/normal-distribution
>
>
>
>Problem
>
>Assume that the test scores of a college entrance exam fits a normal
>distribution. Furthermore, the mean test score is 72, and the standard
>deviation is 15.2. What is the percentage of students scoring 84 or
>more in
>the exam?
>
>
>
>Solution
>
>> pnorm(84, mean=72, sd=15.2, lower.tail=FALSE)
>
>[1] 0.21492
>
>
>
>That is straight forward, however what if I want to know the score the
>best
>30% students are reaching at least. So I know the solution of pnorm but
>want to know its q. How can that be achieved in R?
>
>
>
>Any suggestions?
>
>
>
>/Johannes
>
>	[[alternative HTML version deleted]]
>
>______________________________________________
>R-help at r-project.org mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.