Finding the Fourth Proportional to 1,003.61, 1,505.69 and 418.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.61 : 1,505.69 = 418.42 : x
2. Step 2: Convert to fraction form
   1,003.61/1,505.69 = 418.42/x
3. Step 3: Cross multiply
   1,003.61x = 1,505.69 × 418.42
4. Step 4: Simplify right side
   1,003.61x = 630,005.48
5. Step 5: Solve for x
   x = 630,005.48/1,003.61
6. Step 6: Final answer
   x = 627.74