Finding the Fourth Proportional to 1,066.76, 1,471.72 and 787.66

Step by Step Solution

1. Step 1: Write the proportion equation
   1,066.76 : 1,471.72 = 787.66 : x
2. Step 2: Convert to fraction form
   1,066.76/1,471.72 = 787.66/x
3. Step 3: Cross multiply
   1,066.76x = 1,471.72 × 787.66
4. Step 4: Simplify right side
   1,066.76x = 1,159,214.98
5. Step 5: Solve for x
   x = 1,159,214.98/1,066.76
6. Step 6: Final answer
   x = 1,086.67