Finding the Fourth Proportional to 1,380.11, 1,904.42 and 782.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.11 : 1,904.42 = 782.63 : x
2. Step 2: Convert to fraction form
   1,380.11/1,904.42 = 782.63/x
3. Step 3: Cross multiply
   1,380.11x = 1,904.42 × 782.63
4. Step 4: Simplify right side
   1,380.11x = 1,490,456.22
5. Step 5: Solve for x
   x = 1,490,456.22/1,380.11
6. Step 6: Final answer
   x = 1,079.95