What is MEAN ABSOLUTE DEVIATION and how do you find it?

Given the statements, "a square root of 16 is 4," and "a square root of 9 is -3," complete the following blanks with the correct truth-values. p is and q is , so the statement, "a square root of 16 is 4 or a square root of 9 is -3" is .

Which of these numbers of simulations of an event would be most likely to produce results that are closest to those predicted by probability theory? 15, 20, 5, 10

I’m really confused and need your assist me with this question i’ve never been taught