if comparing float, linux shell, awk

if a is greater than b:

#!/bin/sh
a=$(echo "6.3")
b=$(echo "5.95")
var=$(awk 'BEGIN{ print "'$b'"<"'$a'" }')
if [ "$var" -eq 1 ]; then
echo $a is greater than $b
else
echo $b is greater then $a
fi

if b is greater than a:

#!/bin/sh
a=$(echo "16.3")
b=$(echo "25.95")
var=$(awk 'BEGIN{ print "'$b'"<"'$a'" }')
if [ "$var" -eq 1 ]; then
echo $a is greater than $b
else
echo $b is greater then $a
fi

if b and a is equal:

#!/bin/sh
a=$(echo "6.3")
b=$(echo "6.3")
var=$(awk 'BEGIN{ print "'$b'"=="'$a'" }')
if [ "$var" -eq 0 ]; then
echo $a and $b is different
else
echo $b and $a is equal
fi