Finding the Fourth Proportional to 1,861.81, 2,790.21 and 1,309.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,861.81 : 2,790.21 = 1,309.52 : x
2. Step 2: Convert to fraction form
   1,861.81/2,790.21 = 1,309.52/x
3. Step 3: Cross multiply
   1,861.81x = 2,790.21 × 1,309.52
4. Step 4: Simplify right side
   1,861.81x = 3,653,835.80
5. Step 5: Solve for x
   x = 3,653,835.80/1,861.81
6. Step 6: Final answer
   x = 1,962.52