Finding the Fourth Proportional to 1,172.76, 1,620.55 and 1,115.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.76 : 1,620.55 = 1,115.83 : x
2. Step 2: Convert to fraction form
   1,172.76/1,620.55 = 1,115.83/x
3. Step 3: Cross multiply
   1,172.76x = 1,620.55 × 1,115.83
4. Step 4: Simplify right side
   1,172.76x = 1,808,250.20
5. Step 5: Solve for x
   x = 1,808,250.20/1,172.76
6. Step 6: Final answer
   x = 1,541.88