Finding the Fourth Proportional to 2,112.81, 3,170.42 and 1,072.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,112.81 : 3,170.42 = 1,072.87 : x
2. Step 2: Convert to fraction form
   2,112.81/3,170.42 = 1,072.87/x
3. Step 3: Cross multiply
   2,112.81x = 3,170.42 × 1,072.87
4. Step 4: Simplify right side
   2,112.81x = 3,401,445.14
5. Step 5: Solve for x
   x = 3,401,445.14/2,112.81
6. Step 6: Final answer
   x = 1,609.92