Final answer:
The value of the third number, represented by n, must be greater than 7 for the arithmetic mean of the three numbers to be greater than 11.
Step-by-step explanation:
The question asks to calculate the value of a third number, represented by n, given that the arithmetic mean of three numbers is greater than 11, and the first two numbers are -4 and 30. To solve for n, we use the formula for the arithmetic mean with the provided values.
The arithmetic mean of -4, 30, and n can be found by the formula:
Arithmetic Mean = (Sum of all numbers) / (Number of numbers)
In this case, we have:
Arithmetic Mean = (-4 + 30 + n) / 3 > 11
After calculating the sum and simplifying, we get:
-4 + 30 + n > 33
n > 33 - 26
n > 7
Therefore, the value of n must be greater than 7 for the arithmetic mean of the three numbers to be greater than 11.