The mean of a set of 10 numbers is 16. Two of the numbers (7 and 13) are removed. What is the mean of the 8 remaining numbers?

17.5

Step-by-step explanation:

10 x 16=160. The sum of the numbers is 160.

7 + 13 = 20.

160-20=140.

Now, divide by 8.

17.5

:D

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation: