Finding the Fourth Proportional to 1,003.30, 1,384.54 and 561.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.30 : 1,384.54 = 561.20 : x
2. Step 2: Convert to fraction form
   1,003.30/1,384.54 = 561.20/x
3. Step 3: Cross multiply
   1,003.30x = 1,384.54 × 561.20
4. Step 4: Simplify right side
   1,003.30x = 776,995.52
5. Step 5: Solve for x
   x = 776,995.52/1,003.30
6. Step 6: Final answer
   x = 774.44