Finding the Fourth Proportional to 1,666.56, 2,498.06 and 678.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,666.56 : 2,498.06 = 678.98 : x
2. Step 2: Convert to fraction form
   1,666.56/2,498.06 = 678.98/x
3. Step 3: Cross multiply
   1,666.56x = 2,498.06 × 678.98
4. Step 4: Simplify right side
   1,666.56x = 1,696,132.78
5. Step 5: Solve for x
   x = 1,696,132.78/1,666.56
6. Step 6: Final answer
   x = 1,017.74