Finding the Fourth Proportional to 1,395.52, 1,925.78 and 789.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,395.52 : 1,925.78 = 789.81 : x
2. Step 2: Convert to fraction form
   1,395.52/1,925.78 = 789.81/x
3. Step 3: Cross multiply
   1,395.52x = 1,925.78 × 789.81
4. Step 4: Simplify right side
   1,395.52x = 1,521,000.30
5. Step 5: Solve for x
   x = 1,521,000.30/1,395.52
6. Step 6: Final answer
   x = 1,089.92