Finding the Fourth Proportional to 1,411.61, 2,117.83 and 671.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,411.61 : 2,117.83 = 671.78 : x
2. Step 2: Convert to fraction form
   1,411.61/2,117.83 = 671.78/x
3. Step 3: Cross multiply
   1,411.61x = 2,117.83 × 671.78
4. Step 4: Simplify right side
   1,411.61x = 1,422,719.45
5. Step 5: Solve for x
   x = 1,422,719.45/1,411.61
6. Step 6: Final answer
   x = 1,007.87