Finding the Fourth Proportional to 2,196.80, 3,031.52 and 1,312.64

Step by Step Solution

1. Step 1: Write the proportion equation
   2,196.80 : 3,031.52 = 1,312.64 : x
2. Step 2: Convert to fraction form
   2,196.80/3,031.52 = 1,312.64/x
3. Step 3: Cross multiply
   2,196.80x = 3,031.52 × 1,312.64
4. Step 4: Simplify right side
   2,196.80x = 3,979,294.41
5. Step 5: Solve for x
   x = 3,979,294.41/2,196.80
6. Step 6: Final answer
   x = 1,811.40