Finding the Fourth Proportional to 1,379.72, 1,903.92 and 782.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.72 : 1,903.92 = 782.32 : x
2. Step 2: Convert to fraction form
   1,379.72/1,903.92 = 782.32/x
3. Step 3: Cross multiply
   1,379.72x = 1,903.92 × 782.32
4. Step 4: Simplify right side
   1,379.72x = 1,489,474.69
5. Step 5: Solve for x
   x = 1,489,474.69/1,379.72
6. Step 6: Final answer
   x = 1,079.55