Finding the Fourth Proportional to 1,312.91, 1,811.82 and 789.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.91 : 1,811.82 = 789.24 : x
2. Step 2: Convert to fraction form
   1,312.91/1,811.82 = 789.24/x
3. Step 3: Cross multiply
   1,312.91x = 1,811.82 × 789.24
4. Step 4: Simplify right side
   1,312.91x = 1,429,956.87
5. Step 5: Solve for x
   x = 1,429,956.87/1,312.91
6. Step 6: Final answer
   x = 1,089.15