In a group there are 5 singers, 3 dancers, 2 artists, 1 musician, 1 guitarist…

In a group there are 5 singers, 3 dancers, 2 artists, 1 musician, 1 guitarist and 1 teacher. The average height of the above mentioned people reduces by 2cm if I replace the guitarist with a joker. Find the height of the joker, if the height of the guitarist is 184 cm.