81 is the correct answer
hope it helps you have a good day
How can its diagonal be perpendicular to one of its sides? Since this can be read out of your details! You know point A and C are not adjacent but C and D are. So, AC must be the diagonal which is never perp. to any of the sides (CD)
Easy
sub 2 for x
f(2)=2(2)^3-3(2)^2+7
f(2)=2(8)-3(4)+7
f(2)=16-12+7
f(2)=11
That would a set of 5 numbers in ascending order with 4 being the middle one and the other 4 being the highest possible So it is
2, 3, 4, 9, 10
Mean is 28/5 = 5.6 answer
( I am assuming that each number is different)
Of duplicates is allowed then its 4 4 4 10 10 whose mean is 6.4