port part of r65068

git-svn-id: https://svn.r-project.org/R/branches/R-3-0-branch@65069 00db46b3-68df-0310-9c12-caf00c1e9a41

doc/manual/R-exts.texi

@@ -3872,7 +3872,7 @@ all platforms use those CPUs, and not all@footnote{Not doing so is the
 default on Windows, overridden for the @R{} executables.  It is also the
 default on some Solaris compilers.} which use them configure them to
 allow the use of extended precision.  In particular, ARM CPUs do not
-(currently) have extended precsion nor long doubles.
+(currently) have extended precision nor long doubles.
 
 If you must try to establish a tolerance empirically, configure and
 build @R{} with @option{--disable-long-doubles} and use appropriate