Return 4 or 5 star post at random?

Hi all,

I have looked through this support forum but was unable to find what im looking for so apologies if ive missed the answer.

I am developing a query_posts arguments list to return a random custom post type with a rating of 4 or above.

My current code looks like:

$query_args['post_type'] = 'recipes';
$query_args['post_status'] = 'publish';
$query_args['r_sortby'] = 'highest_rated';
$query_args['r_orderby'] = 'rand';
$query_args['posts_per_page'] = '1';
query_posts($query_args);

This is returning the highest rated recipe. How can I amend to only return a random 4/5 star recipe?

Thanks very much.

https://www.ads-software.com/extend/plugins/wp-postratings/