Finding the Fourth Proportional to 1,061.40, 1,591.55 and 330.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.40 : 1,591.55 = 330.78 : x
2. Step 2: Convert to fraction form
   1,061.40/1,591.55 = 330.78/x
3. Step 3: Cross multiply
   1,061.40x = 1,591.55 × 330.78
4. Step 4: Simplify right side
   1,061.40x = 526,458.46
5. Step 5: Solve for x
   x = 526,458.46/1,061.40
6. Step 6: Final answer
   x = 496.00