this is how i did it? am i right????: i multiplied did 74.5 multiplied by .95 an

this is how i did it? am i right????:
i multiplied did 74.5 multiplied by .95 and got 70.775 (which is the POINTS i need to pass)
then test one i did 72 multiplied by .30 and got 21.6 points
then test two i did 78 multipled by .30 and got 23.4 points
i then added 23.4 and 21.6 points to get 45 points
SO FAR I HAVE 45 POINTS OUT OF THE 70.775 I NEED
i subtracted 45 from 70.775 and got 25.775
so i need 25.775 more points out of the 70.775
in order to figure out what test 3 is i made test 3 = x
the math problem i then did was .35x = 25.775
i got 73.642857 for my final answer am i correct when i say i need a 73.642857 on my final test for my average of the three tests (being worth 95% all together) to be at least a 74.5average?