Finding the Fourth Proportional to 9,891.46, 13,649.61 and 5,642.74

Step by Step Solution

1. Step 1: Write the proportion equation
   9,891.46 : 13,649.61 = 5,642.74 : x
2. Step 2: Convert to fraction form
   9,891.46/13,649.61 = 5,642.74/x
3. Step 3: Cross multiply
   9,891.46x = 13,649.61 × 5,642.74
4. Step 4: Simplify right side
   9,891.46x = 77,021,200.33
5. Step 5: Solve for x
   x = 77,021,200.33/9,891.46
6. Step 6: Final answer
   x = 7,786.64