Finding the Fourth Proportional to 11,663.76, 17,491.59 and 3,870.75

Step by Step Solution

1. Step 1: Write the proportion equation
   11,663.76 : 17,491.59 = 3,870.75 : x
2. Step 2: Convert to fraction form
   11,663.76/17,491.59 = 3,870.75/x
3. Step 3: Cross multiply
   11,663.76x = 17,491.59 × 3,870.75
4. Step 4: Simplify right side
   11,663.76x = 67,705,571.99
5. Step 5: Solve for x
   x = 67,705,571.99/11,663.76
6. Step 6: Final answer
   x = 5,804.78