Finding the Fourth Proportional to 1,395.84, 1,926.12 and 806.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,395.84 : 1,926.12 = 806.40 : x
2. Step 2: Convert to fraction form
   1,395.84/1,926.12 = 806.40/x
3. Step 3: Cross multiply
   1,395.84x = 1,926.12 × 806.40
4. Step 4: Simplify right side
   1,395.84x = 1,553,223.17
5. Step 5: Solve for x
   x = 1,553,223.17/1,395.84
6. Step 6: Final answer
   x = 1,112.75