Finding the Fourth Proportional to 1,003.21, 1,384.48 and 561.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.21 : 1,384.48 = 561.10 : x
2. Step 2: Convert to fraction form
   1,003.21/1,384.48 = 561.10/x
3. Step 3: Cross multiply
   1,003.21x = 1,384.48 × 561.10
4. Step 4: Simplify right side
   1,003.21x = 776,826.86
5. Step 5: Solve for x
   x = 776,826.86/1,003.21
6. Step 6: Final answer
   x = 774.35