Finding the Fourth Proportional to 8,989.80, 12,377.69 and 7,642.76

Step by Step Solution

1. Step 1: Write the proportion equation
   8,989.80 : 12,377.69 = 7,642.76 : x
2. Step 2: Convert to fraction form
   8,989.80/12,377.69 = 7,642.76/x
3. Step 3: Cross multiply
   8,989.80x = 12,377.69 × 7,642.76
4. Step 4: Simplify right side
   8,989.80x = 94,599,613.92
5. Step 5: Solve for x
   x = 94,599,613.92/8,989.80
6. Step 6: Final answer
   x = 10,522.99