Finding the Fourth Proportional to 1,216.95, 1,680.20 and 936.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.95 : 1,680.20 = 936.69 : x
2. Step 2: Convert to fraction form
   1,216.95/1,680.20 = 936.69/x
3. Step 3: Cross multiply
   1,216.95x = 1,680.20 × 936.69
4. Step 4: Simplify right side
   1,216.95x = 1,573,826.54
5. Step 5: Solve for x
   x = 1,573,826.54/1,216.95
6. Step 6: Final answer
   x = 1,293.25