Finding the Fourth Proportional to 1,786.38, 2,677.78 and 861.67

Step by Step Solution

1. Step 1: Write the proportion equation
   1,786.38 : 2,677.78 = 861.67 : x
2. Step 2: Convert to fraction form
   1,786.38/2,677.78 = 861.67/x
3. Step 3: Cross multiply
   1,786.38x = 2,677.78 × 861.67
4. Step 4: Simplify right side
   1,786.38x = 2,307,362.69
5. Step 5: Solve for x
   x = 2,307,362.69/1,786.38
6. Step 6: Final answer
   x = 1,291.64