Finding the Fourth Proportional to 1,079.98, 1,620.62 and 386.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.98 : 1,620.62 = 386.59 : x
2. Step 2: Convert to fraction form
   1,079.98/1,620.62 = 386.59/x
3. Step 3: Cross multiply
   1,079.98x = 1,620.62 × 386.59
4. Step 4: Simplify right side
   1,079.98x = 626,513.55
5. Step 5: Solve for x
   x = 626,513.55/1,079.98
6. Step 6: Final answer
   x = 580.12