Finding the Fourth Proportional to 1,222.41, 1,826.19 and 780.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.41 : 1,826.19 = 780.15 : x
2. Step 2: Convert to fraction form
   1,222.41/1,826.19 = 780.15/x
3. Step 3: Cross multiply
   1,222.41x = 1,826.19 × 780.15
4. Step 4: Simplify right side
   1,222.41x = 1,424,702.13
5. Step 5: Solve for x
   x = 1,424,702.13/1,222.41
6. Step 6: Final answer
   x = 1,165.49