Finding the Fourth Proportional to 2,196.90, 3,031.45 and 1,312.51

Step by Step Solution

1. Step 1: Write the proportion equation
   2,196.90 : 3,031.45 = 1,312.51 : x
2. Step 2: Convert to fraction form
   2,196.90/3,031.45 = 1,312.51/x
3. Step 3: Cross multiply
   2,196.90x = 3,031.45 × 1,312.51
4. Step 4: Simplify right side
   2,196.90x = 3,978,808.44
5. Step 5: Solve for x
   x = 3,978,808.44/2,196.90
6. Step 6: Final answer
   x = 1,811.10