Finding the Fourth Proportional to 897.42, 1,238.31 and 499.05

Step by Step Solution

1. Step 1: Write the proportion equation
   897.42 : 1,238.31 = 499.05 : x
2. Step 2: Convert to fraction form
   897.42/1,238.31 = 499.05/x
3. Step 3: Cross multiply
   897.42x = 1,238.31 × 499.05
4. Step 4: Simplify right side
   897.42x = 617,978.61
5. Step 5: Solve for x
   x = 617,978.61/897.42
6. Step 6: Final answer
   x = 688.62