Finding the Fourth Proportional to 1,409.99, 1,945.72 and 780.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,409.99 : 1,945.72 = 780.54 : x
2. Step 2: Convert to fraction form
   1,409.99/1,945.72 = 780.54/x
3. Step 3: Cross multiply
   1,409.99x = 1,945.72 × 780.54
4. Step 4: Simplify right side
   1,409.99x = 1,518,698.66
5. Step 5: Solve for x
   x = 1,518,698.66/1,409.99
6. Step 6: Final answer
   x = 1,077.10