Finding the Fourth Proportional to 1,081.50, 1,620.89 and 561.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.50 : 1,620.89 = 561.41 : x
2. Step 2: Convert to fraction form
   1,081.50/1,620.89 = 561.41/x
3. Step 3: Cross multiply
   1,081.50x = 1,620.89 × 561.41
4. Step 4: Simplify right side
   1,081.50x = 909,974.99
5. Step 5: Solve for x
   x = 909,974.99/1,081.50
6. Step 6: Final answer
   x = 841.40