Finding the Fourth Proportional to 1,947.87, 2,686.86 and 1,388.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,947.87 : 2,686.86 = 1,388.52 : x
2. Step 2: Convert to fraction form
   1,947.87/2,686.86 = 1,388.52/x
3. Step 3: Cross multiply
   1,947.87x = 2,686.86 × 1,388.52
4. Step 4: Simplify right side
   1,947.87x = 3,730,758.85
5. Step 5: Solve for x
   x = 3,730,758.85/1,947.87
6. Step 6: Final answer
   x = 1,915.30