Finding the Fourth Proportional to 1,409.61, 1,945.22 and 780.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,409.61 : 1,945.22 = 780.12 : x
2. Step 2: Convert to fraction form
   1,409.61/1,945.22 = 780.12/x
3. Step 3: Cross multiply
   1,409.61x = 1,945.22 × 780.12
4. Step 4: Simplify right side
   1,409.61x = 1,517,496.76
5. Step 5: Solve for x
   x = 1,517,496.76/1,409.61
6. Step 6: Final answer
   x = 1,076.54