Finding the Fourth Proportional to 1,870.64, 2,581.36 and 1,031.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,870.64 : 2,581.36 = 1,031.20 : x
2. Step 2: Convert to fraction form
   1,870.64/2,581.36 = 1,031.20/x
3. Step 3: Cross multiply
   1,870.64x = 2,581.36 × 1,031.20
4. Step 4: Simplify right side
   1,870.64x = 2,661,898.43
5. Step 5: Solve for x
   x = 2,661,898.43/1,870.64
6. Step 6: Final answer
   x = 1,422.99