Finding the Fourth Proportional to 1,026.42, 1,538.61 and 478.11

Step by Step Solution

1. Step 1: Write the proportion equation
   1,026.42 : 1,538.61 = 478.11 : x
2. Step 2: Convert to fraction form
   1,026.42/1,538.61 = 478.11/x
3. Step 3: Cross multiply
   1,026.42x = 1,538.61 × 478.11
4. Step 4: Simplify right side
   1,026.42x = 735,624.83
5. Step 5: Solve for x
   x = 735,624.83/1,026.42
6. Step 6: Final answer
   x = 716.69