Finding the Fourth Proportional to 1,680.61, 2,521.79 and 694.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,680.61 : 2,521.79 = 694.15 : x
2. Step 2: Convert to fraction form
   1,680.61/2,521.79 = 694.15/x
3. Step 3: Cross multiply
   1,680.61x = 2,521.79 × 694.15
4. Step 4: Simplify right side
   1,680.61x = 1,750,500.53
5. Step 5: Solve for x
   x = 1,750,500.53/1,680.61
6. Step 6: Final answer
   x = 1,041.59