Finding the Fourth Proportional to 1,111.62, 1,667.42 and 342.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.62 : 1,667.42 = 342.12 : x
2. Step 2: Convert to fraction form
   1,111.62/1,667.42 = 342.12/x
3. Step 3: Cross multiply
   1,111.62x = 1,667.42 × 342.12
4. Step 4: Simplify right side
   1,111.62x = 570,457.73
5. Step 5: Solve for x
   x = 570,457.73/1,111.62
6. Step 6: Final answer
   x = 513.18