The table given below shows the sales of bikes and cars of five companies.

Companies	Bike	Car
P	200	1200
Q	100	300
R	500	700
S	600	1000
T	800	800

J1 = The average sale of bikes of company P, Q and R.

J2 = The average sale of cars of company R, S and T.

What is the value of (J1 ∶ J2)?