The average of 5 numbers is 8.5. Four of the numbers are 9.2, 3.4, 6.5,and 7.4. What is the fifth number?

To find the fifth number, we can use the formula for the average:

Average = (Sum of the numbers) / (Number of numbers)
We know that the average is 8.5 and there are 5 numbers in total. Therefore, the sum of the 5 numbers is 8.5 * 5 = 42.5.
We also have the sum of four of the numbers, which is 9.2 + 3.4 + 6.5 + 7.4 = 26.5.
To find the fifth number, we can subtract the sum of the four numbers from the sum of all five numbers:
42.5 - 26.5 = 16.
Therefore, the fifth number is 16. Answer: \boxed{16}.

To find the fifth number, we can use the average formula: average = sum of all numbers / total numbers.

In this case, the average is given as 8.5 and the total numbers are 5.

First, we need to find the sum of the four given numbers: 9.2 + 3.4 + 6.5 + 7.4 = 26.5.

Next, we can substitute the values into the average formula: 8.5 = 26.5 + fifth number / 5.

To isolate the fifth number, we can multiply both sides of the equation by 5:

8.5 * 5 = 26.5 + fifth number.

This simplifies to: 42.5 = 26.5 + fifth number.

To isolate the fifth number, we subtract 26.5 from both sides: 42.5 - 26.5 = fifth number.

The calculation gives us: 16 = fifth number.

Therefore, the fifth number is 16.

To find the fifth number, we can use the formula for calculating the average:

Average = (Sum of all numbers) / (Number of numbers)

Let's plug in the given values:

Average = 8.5
Number of numbers = 5 (including the fifth number)
Sum of all numbers = 9.2 + 3.4 + 6.5 + 7.4 + Fifth number

Now, we can rearrange the formula to solve for the fifth number:

Sum of all numbers = Average * Number of numbers
9.2 + 3.4 + 6.5 + 7.4 + Fifth number = 8.5 * 5

Multiply the average by the number of numbers:

9.2 + 3.4 + 6.5 + 7.4 + Fifth number = 42.5

Now, subtract the sum of the known numbers from both sides of the equation to isolate the fifth number:

Fifth number = 42.5 - (9.2 + 3.4 + 6.5 + 7.4)

Calculate the sum of the known numbers:

Fifth number = 42.5 - 26.5

Perform the subtraction:

Fifth number = 16

So, the fifth number is 16.