Finding the Fourth Proportional to 1,290.37, 1,780.14 and 766.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.37 : 1,780.14 = 766.10 : x
2. Step 2: Convert to fraction form
   1,290.37/1,780.14 = 766.10/x
3. Step 3: Cross multiply
   1,290.37x = 1,780.14 × 766.10
4. Step 4: Simplify right side
   1,290.37x = 1,363,752.52
5. Step 5: Solve for x
   x = 1,363,752.52/1,290.37
6. Step 6: Final answer
   x = 1,056.87