Finding the Fourth Proportional to 1,385.69, 1,912.20 and 756.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.69 : 1,912.20 = 756.20 : x
2. Step 2: Convert to fraction form
   1,385.69/1,912.20 = 756.20/x
3. Step 3: Cross multiply
   1,385.69x = 1,912.20 × 756.20
4. Step 4: Simplify right side
   1,385.69x = 1,445,996.08
5. Step 5: Solve for x
   x = 1,445,996.08/1,385.69
6. Step 6: Final answer
   x = 1,043.52