Finding the Fourth Proportional to 1,285.31, 1,773.60 and 788.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,285.31 : 1,773.60 = 788.09 : x
2. Step 2: Convert to fraction form
   1,285.31/1,773.60 = 788.09/x
3. Step 3: Cross multiply
   1,285.31x = 1,773.60 × 788.09
4. Step 4: Simplify right side
   1,285.31x = 1,397,756.42
5. Step 5: Solve for x
   x = 1,397,756.42/1,285.31
6. Step 6: Final answer
   x = 1,087.49