Finding the Fourth Proportional to 1,415.33, 2,124.24 and 685.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,415.33 : 2,124.24 = 685.45 : x
2. Step 2: Convert to fraction form
   1,415.33/2,124.24 = 685.45/x
3. Step 3: Cross multiply
   1,415.33x = 2,124.24 × 685.45
4. Step 4: Simplify right side
   1,415.33x = 1,456,060.31
5. Step 5: Solve for x
   x = 1,456,060.31/1,415.33
6. Step 6: Final answer
   x = 1,028.78