Fix required answer tolerance display

Author: gajennings

OpenProblemLibrary/AlfredUniv/anton8e/chapter2/2.4/prob3.pg

@@ -43,7 +43,7 @@ Context()->{format}{number} = "";
 ## $x1 is the point where we will estimate the derivative.
 $x1 = random(.001, .01,.0001);
 $epsilon = random(.0001,.0004,.00001);
-$answertolerance = 0.00001;
+$answertolerance = Real(0.00001);
 # check inputs_ref to see if the student modified $dh, otherwise we set it to
 ## 0.0001.
 if (defined( ${$inputs_ref}{'dh'}) ) {
@@ -53,7 +53,7 @@ else {
 	 $dh = .0001
 }
 
-## Define the function f and it's derivative
+## Define the function f and its derivative
 $f = Formula("x^2+x");
 $f->perlFunction(f1);
 $dfdx = $f->D('x');