Question 634800
After five English tests, Michael's mean mark was 65.
In the next three English tests he scored 70,75 and 80.
 Find Michael's mean mark for all of these English tests.
:
He took a total of 8 tests, 
av = {{{(5(65)+70+75+80)/8}}}
av = {{{(325+225)/8}}}
av = {{{550/8}}}
av = 68.75%