[pstricks] pscurve not hitting designated points

[Rich Shepard]

   I'm trying to draw a normal curve that peaks (y=1.0) at x=6. The following
lyx code doesn't do it. I get a flattened curve (peak about 8,0.25). What
have I missed here, please?

Thanks,

Rich

-- 
Dr. Richard B. Shepard, President
Applied Ecosystem Services, Inc. (TM)
<http://www.appl-ecosys.com>   Voice: 503-667-4517   Fax: 503-667-8863
======================================================================
#LyX 1.3 created this file. For more info see http://www.lyx.org/
\lyxformat 221
\textclass article
\begin_preamble
\usepackage{pst-plot} 
\usepackage{pst-pdf}
\end_preamble
\language american
\inputencoding auto
\fontscheme palatino
\graphics default
\paperfontsize default
\spacing single 
\papersize letterpaper
\paperpackage a4
\use_geometry 0
\use_amsmath 1
\use_natbib 0
\use_numerical_citations 0
\paperorientation portrait
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\defskip medskip
\quotes_language english
\quotes_times 2
\papercolumns 1
\papersides 2
\paperpagestyle empty

\layout Standard


\begin_inset Float figure
wide false
collapsed false

\layout Standard
\align center

\begin_inset ERT
status Open

\layout Standard

\backslash 
psset{linecolor=blue}
\layout Standard

\backslash 
begin{pspicture}(0,4)(9,5)
\layout Standard

\backslash 
psaxes[dx=2,Dx=2,Ox=2, dy=1, Dy=.25](0,0)(8,4)
\newline

\backslash 
pscurve[linecolor=red, linewidth=2pt](0,0)(4.5,.5)(6,1)(7.5,.5)(10,0)
\newline

\backslash 
rput(4,-1){Height (in feet)}
\newline

\backslash 
rput{90}(-1.5,2){Membership, $
\backslash 
mu$(x)}
\newline

\backslash 
end{pspicture}
\layout Standard

\end_inset


\end_inset


\the_end