Finding the Fourth Proportional to 2,606.76, 3,900.90 and 1,911.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,606.76 : 3,900.90 = 1,911.72 : x
2. Step 2: Convert to fraction form
   2,606.76/3,900.90 = 1,911.72/x
3. Step 3: Cross multiply
   2,606.76x = 3,900.90 × 1,911.72
4. Step 4: Simplify right side
   2,606.76x = 7,457,428.55
5. Step 5: Solve for x
   x = 7,457,428.55/2,606.76
6. Step 6: Final answer
   x = 2,860.80