Finding the Fourth Proportional to 2,109.89, 3,165.22 and 722.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.89 : 3,165.22 = 722.90 : x
2. Step 2: Convert to fraction form
   2,109.89/3,165.22 = 722.90/x
3. Step 3: Cross multiply
   2,109.89x = 3,165.22 × 722.90
4. Step 4: Simplify right side
   2,109.89x = 2,288,137.54
5. Step 5: Solve for x
   x = 2,288,137.54/2,109.89
6. Step 6: Final answer
   x = 1,084.48