Simplify suqrt. -81

a) -9i
b) 9i
c) -9
d) 9

If a fair 6 sided cube is rolled 60 times, theoretically how many times should you expect to roll a 4 or a 5?

Match each expression with its simplified form.

The administrator of a large assisted living facility wanted to know the average age of the residents living at the facility. he randomly selected 12 residents and determined their age, listed here: 80, 65, 75, 83, 68, 73, 88, 79, 94, 72, 79, 68 what's the average age of the sample of residents? a. 79 years old b. 68 years old c. 75 years old d. 77 years old