Finding the Fourth Proportional to 2,196.60, 3,031.47 and 1,312.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,196.60 : 3,031.47 = 1,312.89 : x
2. Step 2: Convert to fraction form
   2,196.60/3,031.47 = 1,312.89/x
3. Step 3: Cross multiply
   2,196.60x = 3,031.47 × 1,312.89
4. Step 4: Simplify right side
   2,196.60x = 3,979,986.65
5. Step 5: Solve for x
   x = 3,979,986.65/2,196.60
6. Step 6: Final answer
   x = 1,811.89