I click a radio button which updates a hidden field with a value for a Tax Rate based on the province selection.

// Set Tax Rate
$(document).ready(function() {

  $('.province input').on('click', function() {

     $('.taxrate input').val($(this).val()).trigger('change');

  });

});

I then use the following code ( I realize this may not be the most efficient method but with limited JQuery experience I essentially modified one of your code examples to get this to work) to calculate the Tax based on the chosen rate.

// Calculate the Tax
$(document).ready(function () {
    $('.cf-table-block').on('blur', 'input', sumtotal);
    $('.taxrate').on('blur', 'input', sumtotal);
    $('.subtotal').on('blur', 'input', sumtotal);
    $('.province').on('blur', 'input', sumtotal);
    function sumtotal() {
        var sum = 0;
        $('.cf-table-block tbody tr').each(function () {
//            var s = 0;
//            s = parseNumber($(this).find('.price input').val()) * parseNumber($(this).find('.quantity input').val());
//            $(this).find('.subtotal input').val(s);
//            sum += s;
            sum += parseNumber($('.taxrate input').val()) * parseNumber($('.subtotal input').val());
        });
        $('.tax input').val((sum).toFixed(2));
    }
    function parseNumber(n) {
        var f = parseFloat(n); //Convert to float number.
        return isNaN(f) ? 0 : f; //treat invalid input as 0;
    }
});

I added this line above the the Tax Rate will calculate when the Province radio button is selected "province' is my css value.

 $('.province').on('blur', 'input', sumtotal);

This works great and updates when the radio button loses focus. Is it possible to have the Tax Rate update on click.

I tried changing the line to:

$('.province').on('click', 'blur', 'input', sumtotal);

or 

$('.province').on('focus', 'blur', 'input', sumtotal);

but these Methods do not seem valid being used in the above line of code.