Finding the Fourth Proportional to 1,401.78, 2,102.86 and 670.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.78 : 2,102.86 = 670.74 : x
2. Step 2: Convert to fraction form
   1,401.78/2,102.86 = 670.74/x
3. Step 3: Cross multiply
   1,401.78x = 2,102.86 × 670.74
4. Step 4: Simplify right side
   1,401.78x = 1,410,472.32
5. Step 5: Solve for x
   x = 1,410,472.32/1,401.78
6. Step 6: Final answer
   x = 1,006.20