Finding the Fourth Proportional to 1,385.69, 1,913.15 and 1,055.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.69 : 1,913.15 = 1,055.81 : x
2. Step 2: Convert to fraction form
   1,385.69/1,913.15 = 1,055.81/x
3. Step 3: Cross multiply
   1,385.69x = 1,913.15 × 1,055.81
4. Step 4: Simplify right side
   1,385.69x = 2,019,930.32
5. Step 5: Solve for x
   x = 2,019,930.32/1,385.69
6. Step 6: Final answer
   x = 1,457.71