Teresa has scored 77, 80, 63, 61 and 92 on previous test what score does she need on her next test on her average will be 77

Average = 77 = (77+80+63+61+92+Next test) / 6

Therefore, 77*6=77+80+63+61+92+Next test

Next test score = (77*6) - (77+80+63+61+92) = 89

89, because if you try dividing 373 by 5 it’s 74, so first try adding 77 to 373 which is 450 and divide that by 6 which is 75. Now what you have to do is to add numbers to 373 and divide it by 6 until you get an average of 77. Ex: 373+78=451 451 divided by 6 is 75.16 which isn’t right so you just keep trying different numbers