Finding the Fourth Proportional to 1,557.51, 2,336.61 and 680.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,557.51 : 2,336.61 = 680.15 : x
2. Step 2: Convert to fraction form
   1,557.51/2,336.61 = 680.15/x
3. Step 3: Cross multiply
   1,557.51x = 2,336.61 × 680.15
4. Step 4: Simplify right side
   1,557.51x = 1,589,241.89
5. Step 5: Solve for x
   x = 1,589,241.89/1,557.51
6. Step 6: Final answer
   x = 1,020.38