Finding the Fourth Proportional to 9,886.77, 13,642.43 and 5,694.21

Step by Step Solution

1. Step 1: Write the proportion equation
   9,886.77 : 13,642.43 = 5,694.21 : x
2. Step 2: Convert to fraction form
   9,886.77/13,642.43 = 5,694.21/x
3. Step 3: Cross multiply
   9,886.77x = 13,642.43 × 5,694.21
4. Step 4: Simplify right side
   9,886.77x = 77,682,832.86
5. Step 5: Solve for x
   x = 77,682,832.86/9,886.77
6. Step 6: Final answer
   x = 7,857.25