Finding the Fourth Proportional to 1,387.46, 1,913.81 and 1,055.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.46 : 1,913.81 = 1,055.16 : x
2. Step 2: Convert to fraction form
   1,387.46/1,913.81 = 1,055.16/x
3. Step 3: Cross multiply
   1,387.46x = 1,913.81 × 1,055.16
4. Step 4: Simplify right side
   1,387.46x = 2,019,375.76
5. Step 5: Solve for x
   x = 2,019,375.76/1,387.46
6. Step 6: Final answer
   x = 1,455.45