Finding the Fourth Proportional to 1,477.59, 2,215.66 and 861.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,477.59 : 2,215.66 = 861.45 : x
2. Step 2: Convert to fraction form
   1,477.59/2,215.66 = 861.45/x
3. Step 3: Cross multiply
   1,477.59x = 2,215.66 × 861.45
4. Step 4: Simplify right side
   1,477.59x = 1,908,680.31
5. Step 5: Solve for x
   x = 1,908,680.31/1,477.59
6. Step 6: Final answer
   x = 1,291.75