Finding the Fourth Proportional to 2,196.78, 3,031.54 and 1,312.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,196.78 : 3,031.54 = 1,312.57 : x
2. Step 2: Convert to fraction form
   2,196.78/3,031.54 = 1,312.57/x
3. Step 3: Cross multiply
   2,196.78x = 3,031.54 × 1,312.57
4. Step 4: Simplify right side
   2,196.78x = 3,979,108.46
5. Step 5: Solve for x
   x = 3,979,108.46/2,196.78
6. Step 6: Final answer
   x = 1,811.34