Finding the Fourth Proportional to 1,069.34, 1,603.53 and 338.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,069.34 : 1,603.53 = 338.78 : x
2. Step 2: Convert to fraction form
   1,069.34/1,603.53 = 338.78/x
3. Step 3: Cross multiply
   1,069.34x = 1,603.53 × 338.78
4. Step 4: Simplify right side
   1,069.34x = 543,243.89
5. Step 5: Solve for x
   x = 543,243.89/1,069.34
6. Step 6: Final answer
   x = 508.02