Finding the Fourth Proportional to 2,591.67, 3,887.91 and 859.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,591.67 : 3,887.91 = 859.89 : x
2. Step 2: Convert to fraction form
   2,591.67/3,887.91 = 859.89/x
3. Step 3: Cross multiply
   2,591.67x = 3,887.91 × 859.89
4. Step 4: Simplify right side
   2,591.67x = 3,343,174.93
5. Step 5: Solve for x
   x = 3,343,174.93/2,591.67
6. Step 6: Final answer
   x = 1,289.97