Finding the Fourth Proportional to 1,680.72, 2,521.21 and 510.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,680.72 : 2,521.21 = 510.82 : x
2. Step 2: Convert to fraction form
   1,680.72/2,521.21 = 510.82/x
3. Step 3: Cross multiply
   1,680.72x = 2,521.21 × 510.82
4. Step 4: Simplify right side
   1,680.72x = 1,287,891.43
5. Step 5: Solve for x
   x = 1,287,891.43/1,680.72
6. Step 6: Final answer
   x = 766.27