Finding the Fourth Proportional to 1,807.98, 2,713.78 and 1,221.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,807.98 : 2,713.78 = 1,221.12 : x
2. Step 2: Convert to fraction form
   1,807.98/2,713.78 = 1,221.12/x
3. Step 3: Cross multiply
   1,807.98x = 2,713.78 × 1,221.12
4. Step 4: Simplify right side
   1,807.98x = 3,313,851.03
5. Step 5: Solve for x
   x = 3,313,851.03/1,807.98
6. Step 6: Final answer
   x = 1,832.90