Finding the Fourth Proportional to 1,238.02, 1,855.91 and 457.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.02 : 1,855.91 = 457.50 : x
2. Step 2: Convert to fraction form
   1,238.02/1,855.91 = 457.50/x
3. Step 3: Cross multiply
   1,238.02x = 1,855.91 × 457.50
4. Step 4: Simplify right side
   1,238.02x = 849,078.83
5. Step 5: Solve for x
   x = 849,078.83/1,238.02
6. Step 6: Final answer
   x = 685.84