Finding the Fourth Proportional to 1,228.69, 1,695.56 and 786.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,228.69 : 1,695.56 = 786.50 : x
2. Step 2: Convert to fraction form
   1,228.69/1,695.56 = 786.50/x
3. Step 3: Cross multiply
   1,228.69x = 1,695.56 × 786.50
4. Step 4: Simplify right side
   1,228.69x = 1,333,557.94
5. Step 5: Solve for x
   x = 1,333,557.94/1,228.69
6. Step 6: Final answer
   x = 1,085.35