Finding the Fourth Proportional to 1,061.01, 1,591.10 and 320.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.01 : 1,591.10 = 320.39 : x
2. Step 2: Convert to fraction form
   1,061.01/1,591.10 = 320.39/x
3. Step 3: Cross multiply
   1,061.01x = 1,591.10 × 320.39
4. Step 4: Simplify right side
   1,061.01x = 509,772.53
5. Step 5: Solve for x
   x = 509,772.53/1,061.01
6. Step 6: Final answer
   x = 480.46