Three over four divided by seven times three

I'm assuming that this is  .. 

(3/4) / (7 x 3) =

(3/4) / 21=

(3/4) / (21 / 1) =   "keep"..."change"..."flip'

(3/4) x ( 1/21) =    switch denominators.....this is often a handy trick in multiplying fractions

(3/21) x (1/4) =     and 3/21  = 1/7

(1/7) x (1/4) =

1/28

0.321428571