Finding the Fourth Proportional to 9,890.65, 13,648.41 and 5,641.89

Step by Step Solution

1. Step 1: Write the proportion equation
   9,890.65 : 13,648.41 = 5,641.89 : x
2. Step 2: Convert to fraction form
   9,890.65/13,648.41 = 5,641.89/x
3. Step 3: Cross multiply
   9,890.65x = 13,648.41 × 5,641.89
4. Step 4: Simplify right side
   9,890.65x = 77,002,827.89
5. Step 5: Solve for x
   x = 77,002,827.89/9,890.65
6. Step 6: Final answer
   x = 7,785.42