Finding the Fourth Proportional to 3,420.04, 5,128.96 and 1,111

Step by Step Solution

1. Step 1: Write the proportion equation
   3,420.04 : 5,128.96 = 1,111 : x
2. Step 2: Convert to fraction form
   3,420.04/5,128.96 = 1,111/x
3. Step 3: Cross multiply
   3,420.04x = 5,128.96 × 1,111
4. Step 4: Simplify right side
   3,420.04x = 5,698,274.56
5. Step 5: Solve for x
   x = 5,698,274.56/3,420.04
6. Step 6: Final answer
   x = 1,666.14