Finding the Fourth Proportional to 1,238.71, 1,856.83 and 620.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.71 : 1,856.83 = 620.53 : x
2. Step 2: Convert to fraction form
   1,238.71/1,856.83 = 620.53/x
3. Step 3: Cross multiply
   1,238.71x = 1,856.83 × 620.53
4. Step 4: Simplify right side
   1,238.71x = 1,152,218.72
5. Step 5: Solve for x
   x = 1,152,218.72/1,238.71
6. Step 6: Final answer
   x = 930.18