Finding the Fourth Proportional to 1,385.93, 1,912.74 and 788.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.93 : 1,912.74 = 788.56 : x
2. Step 2: Convert to fraction form
   1,385.93/1,912.74 = 788.56/x
3. Step 3: Cross multiply
   1,385.93x = 1,912.74 × 788.56
4. Step 4: Simplify right side
   1,385.93x = 1,508,310.25
5. Step 5: Solve for x
   x = 1,508,310.25/1,385.93
6. Step 6: Final answer
   x = 1,088.30