Finding the Fourth Proportional to 2,086.12, 3,128.37 and 1,111.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.12 : 3,128.37 = 1,111.69 : x
2. Step 2: Convert to fraction form
   2,086.12/3,128.37 = 1,111.69/x
3. Step 3: Cross multiply
   2,086.12x = 3,128.37 × 1,111.69
4. Step 4: Simplify right side
   2,086.12x = 3,477,777.65
5. Step 5: Solve for x
   x = 3,477,777.65/2,086.12
6. Step 6: Final answer
   x = 1,667.10