Finding the Fourth Proportional to 7,870.77, 10,866.89 and 4,891.05

Step by Step Solution

1. Step 1: Write the proportion equation
   7,870.77 : 10,866.89 = 4,891.05 : x
2. Step 2: Convert to fraction form
   7,870.77/10,866.89 = 4,891.05/x
3. Step 3: Cross multiply
   7,870.77x = 10,866.89 × 4,891.05
4. Step 4: Simplify right side
   7,870.77x = 53,150,477.88
5. Step 5: Solve for x
   x = 53,150,477.88/7,870.77
6. Step 6: Final answer
   x = 6,752.89