Finding the Fourth Proportional to 7,663.61, 10,620.16 and 7,515.99

Step by Step Solution

1. Step 1: Write the proportion equation
   7,663.61 : 10,620.16 = 7,515.99 : x
2. Step 2: Convert to fraction form
   7,663.61/10,620.16 = 7,515.99/x
3. Step 3: Cross multiply
   7,663.61x = 10,620.16 × 7,515.99
4. Step 4: Simplify right side
   7,663.61x = 79,821,039.85
5. Step 5: Solve for x
   x = 79,821,039.85/7,663.61
6. Step 6: Final answer
   x = 10,415.59