Finding the Fourth Proportional to 2,109.24, 3,172.08 and 1,781.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.24 : 3,172.08 = 1,781.20 : x
2. Step 2: Convert to fraction form
   2,109.24/3,172.08 = 1,781.20/x
3. Step 3: Cross multiply
   2,109.24x = 3,172.08 × 1,781.20
4. Step 4: Simplify right side
   2,109.24x = 5,650,108.90
5. Step 5: Solve for x
   x = 5,650,108.90/2,109.24
6. Step 6: Final answer
   x = 2,678.74