Answer:
73
Step-by-step explanation:
to find the mean you need to add up all grades and divide if by the number of terms you added
(82 + 88 + x) ÷ 3 = 69 (since we don't know the third grade let's call it x)
170 + x = 69 × 3
x = 37
if the digits transposed the the actual grade would be 73
Hope you could understand.
If you have any query, feel free to ask.
The answer would be 105, it's square root is approximately 10.2469 <span />
Its 23, you do the times first then add.
3x5=15
15+8=23