Finding the Fourth Proportional to 8,969.91, 12,379.17 and 4,991.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,969.91 : 12,379.17 = 4,991.31 : x
2. Step 2: Convert to fraction form
   8,969.91/12,379.17 = 4,991.31/x
3. Step 3: Cross multiply
   8,969.91x = 12,379.17 × 4,991.31
4. Step 4: Simplify right side
   8,969.91x = 61,788,275.01
5. Step 5: Solve for x
   x = 61,788,275.01/8,969.91
6. Step 6: Final answer
   x = 6,888.39