Finding the Fourth Proportional to 1,379.97, 1,904.40 and 782.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.97 : 1,904.40 = 782.45 : x
2. Step 2: Convert to fraction form
   1,379.97/1,904.40 = 782.45/x
3. Step 3: Cross multiply
   1,379.97x = 1,904.40 × 782.45
4. Step 4: Simplify right side
   1,379.97x = 1,490,097.78
5. Step 5: Solve for x
   x = 1,490,097.78/1,379.97
6. Step 6: Final answer
   x = 1,079.80