Finding the Fourth Proportional to 1,046.72, 1,570.20 and 388.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,046.72 : 1,570.20 = 388.58 : x
2. Step 2: Convert to fraction form
   1,046.72/1,570.20 = 388.58/x
3. Step 3: Cross multiply
   1,046.72x = 1,570.20 × 388.58
4. Step 4: Simplify right side
   1,046.72x = 610,148.32
5. Step 5: Solve for x
   x = 610,148.32/1,046.72
6. Step 6: Final answer
   x = 582.91