Finding the Fourth Proportional to 12,690.77, 17,515.28 and 7,655.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,690.77 : 17,515.28 = 7,655.72 : x
2. Step 2: Convert to fraction form
   12,690.77/17,515.28 = 7,655.72/x
3. Step 3: Cross multiply
   12,690.77x = 17,515.28 × 7,655.72
4. Step 4: Simplify right side
   12,690.77x = 134,091,991.83
5. Step 5: Solve for x
   x = 134,091,991.83/12,690.77
6. Step 6: Final answer
   x = 10,566.10