Finding the Fourth Proportional to 1,018.58, 1,528.30 and 498.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.58 : 1,528.30 = 498.30 : x
2. Step 2: Convert to fraction form
   1,018.58/1,528.30 = 498.30/x
3. Step 3: Cross multiply
   1,018.58x = 1,528.30 × 498.30
4. Step 4: Simplify right side
   1,018.58x = 761,551.89
5. Step 5: Solve for x
   x = 761,551.89/1,018.58
6. Step 6: Final answer
   x = 747.66