Finding the Fourth Proportional to 1,339.98, 2,009.98 and 415.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.98 : 2,009.98 = 415.52 : x
2. Step 2: Convert to fraction form
   1,339.98/2,009.98 = 415.52/x
3. Step 3: Cross multiply
   1,339.98x = 2,009.98 × 415.52
4. Step 4: Simplify right side
   1,339.98x = 835,186.89
5. Step 5: Solve for x
   x = 835,186.89/1,339.98
6. Step 6: Final answer
   x = 623.28