Finding the Fourth Proportional to 1,079.41, 1,620.56 and 641.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.41 : 1,620.56 = 641.47 : x
2. Step 2: Convert to fraction form
   1,079.41/1,620.56 = 641.47/x
3. Step 3: Cross multiply
   1,079.41x = 1,620.56 × 641.47
4. Step 4: Simplify right side
   1,079.41x = 1,039,540.62
5. Step 5: Solve for x
   x = 1,039,540.62/1,079.41
6. Step 6: Final answer
   x = 963.06