Finding the Fourth Proportional to 1,767.31, 2,651.72 and 671.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,767.31 : 2,651.72 = 671.78 : x
2. Step 2: Convert to fraction form
   1,767.31/2,651.72 = 671.78/x
3. Step 3: Cross multiply
   1,767.31x = 2,651.72 × 671.78
4. Step 4: Simplify right side
   1,767.31x = 1,781,372.46
5. Step 5: Solve for x
   x = 1,781,372.46/1,767.31
6. Step 6: Final answer
   x = 1,007.96