Finding the Fourth Proportional to 1,379.61, 1,903.72 and 782.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.61 : 1,903.72 = 782.13 : x
2. Step 2: Convert to fraction form
   1,379.61/1,903.72 = 782.13/x
3. Step 3: Cross multiply
   1,379.61x = 1,903.72 × 782.13
4. Step 4: Simplify right side
   1,379.61x = 1,488,956.52
5. Step 5: Solve for x
   x = 1,488,956.52/1,379.61
6. Step 6: Final answer
   x = 1,079.26