Finding the Fourth Proportional to 1,310.82, 1,809.11 and 1,200.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,310.82 : 1,809.11 = 1,200.10 : x
2. Step 2: Convert to fraction form
   1,310.82/1,809.11 = 1,200.10/x
3. Step 3: Cross multiply
   1,310.82x = 1,809.11 × 1,200.10
4. Step 4: Simplify right side
   1,310.82x = 2,171,097.86
5. Step 5: Solve for x
   x = 2,171,097.86/1,310.82
6. Step 6: Final answer
   x = 1,656.29