Finding the Fourth Proportional to 1,906.13, 2,857.78 and 1,288.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,906.13 : 2,857.78 = 1,288.10 : x
2. Step 2: Convert to fraction form
   1,906.13/2,857.78 = 1,288.10/x
3. Step 3: Cross multiply
   1,906.13x = 2,857.78 × 1,288.10
4. Step 4: Simplify right side
   1,906.13x = 3,681,099.98
5. Step 5: Solve for x
   x = 3,681,099.98/1,906.13
6. Step 6: Final answer
   x = 1,931.19