Finding the Fourth Proportional to 3,418.76, 5,128.78 and 1,109.96

Step by Step Solution

1. Step 1: Write the proportion equation
   3,418.76 : 5,128.78 = 1,109.96 : x
2. Step 2: Convert to fraction form
   3,418.76/5,128.78 = 1,109.96/x
3. Step 3: Cross multiply
   3,418.76x = 5,128.78 × 1,109.96
4. Step 4: Simplify right side
   3,418.76x = 5,692,740.65
5. Step 5: Solve for x
   x = 5,692,740.65/3,418.76
6. Step 6: Final answer
   x = 1,665.15