question: public final String toString ( ) { StringBuffer text = new StringBuffer ( ) ; text . append ( "Print statistic values of instances (" + first + "-" + last + "\n" ) ; text . append ( "    Number of instances:\t" + numInstances + "\n" ) ; text . append ( "    NUmber of instances with unknowns:\t" + missingInstances + "\n" ) ; text . append ( "    Attribute:\t\t\t:" + attr + "\n" ) ; text . append ( "    Sum:\t\t\t" + sum + "\n" ) ; text . append ( "    Squared sum:\t\t" + sqrSum + "\n" ) ; text . append ( "    Stanard Deviation:\t\t" + sd + "\n" ) ; return text . toString ( ) ; }
target:  Converts the stats to a string