Finding the Fourth Proportional to 1,385.53, 1,912.06 and 788.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.53 : 1,912.06 = 788.12 : x
2. Step 2: Convert to fraction form
   1,385.53/1,912.06 = 788.12/x
3. Step 3: Cross multiply
   1,385.53x = 1,912.06 × 788.12
4. Step 4: Simplify right side
   1,385.53x = 1,506,921.20
5. Step 5: Solve for x
   x = 1,506,921.20/1,385.53
6. Step 6: Final answer
   x = 1,087.62