Finding the Fourth Proportional to 1,961.72, 2,705.41 and 1,288.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,961.72 : 2,705.41 = 1,288.92 : x
2. Step 2: Convert to fraction form
   1,961.72/2,705.41 = 1,288.92/x
3. Step 3: Cross multiply
   1,961.72x = 2,705.41 × 1,288.92
4. Step 4: Simplify right side
   1,961.72x = 3,487,057.06
5. Step 5: Solve for x
   x = 3,487,057.06/1,961.72
6. Step 6: Final answer
   x = 1,777.55