Finding the Fourth Proportional to 1,477.55, 2,215.62 and 861.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,477.55 : 2,215.62 = 861.43 : x
2. Step 2: Convert to fraction form
   1,477.55/2,215.62 = 861.43/x
3. Step 3: Cross multiply
   1,477.55x = 2,215.62 × 861.43
4. Step 4: Simplify right side
   1,477.55x = 1,908,601.54
5. Step 5: Solve for x
   x = 1,908,601.54/1,477.55
6. Step 6: Final answer
   x = 1,291.73