Finding the Fourth Proportional to 1,397.94, 1,929.12 and 808.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.94 : 1,929.12 = 808.56 : x
2. Step 2: Convert to fraction form
   1,397.94/1,929.12 = 808.56/x
3. Step 3: Cross multiply
   1,397.94x = 1,929.12 × 808.56
4. Step 4: Simplify right side
   1,397.94x = 1,559,809.27
5. Step 5: Solve for x
   x = 1,559,809.27/1,397.94
6. Step 6: Final answer
   x = 1,115.79