Finding the Fourth Proportional to 1,206.86, 1,664.71 and 763.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,206.86 : 1,664.71 = 763.99 : x
2. Step 2: Convert to fraction form
   1,206.86/1,664.71 = 763.99/x
3. Step 3: Cross multiply
   1,206.86x = 1,664.71 × 763.99
4. Step 4: Simplify right side
   1,206.86x = 1,271,815.72
5. Step 5: Solve for x
   x = 1,271,815.72/1,206.86
6. Step 6: Final answer
   x = 1,053.83