Finding the Fourth Proportional to 1,385.71, 1,913.07 and 1,306.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.71 : 1,913.07 = 1,306.89 : x
2. Step 2: Convert to fraction form
   1,385.71/1,913.07 = 1,306.89/x
3. Step 3: Cross multiply
   1,385.71x = 1,913.07 × 1,306.89
4. Step 4: Simplify right side
   1,385.71x = 2,500,162.49
5. Step 5: Solve for x
   x = 2,500,162.49/1,385.71
6. Step 6: Final answer
   x = 1,804.25