Finding the Fourth Proportional to 2,142.40, 2,956.55 and 1,210.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.40 : 2,956.55 = 1,210.90 : x
2. Step 2: Convert to fraction form
   2,142.40/2,956.55 = 1,210.90/x
3. Step 3: Cross multiply
   2,142.40x = 2,956.55 × 1,210.90
4. Step 4: Simplify right side
   2,142.40x = 3,580,086.40
5. Step 5: Solve for x
   x = 3,580,086.40/2,142.40
6. Step 6: Final answer
   x = 1,671.06