Finding the Fourth Proportional to 11,783.87, 17,665.86 and 5,115.34

Step by Step Solution

1. Step 1: Write the proportion equation
   11,783.87 : 17,665.86 = 5,115.34 : x
2. Step 2: Convert to fraction form
   11,783.87/17,665.86 = 5,115.34/x
3. Step 3: Cross multiply
   11,783.87x = 17,665.86 × 5,115.34
4. Step 4: Simplify right side
   11,783.87x = 90,366,921.56
5. Step 5: Solve for x
   x = 90,366,921.56/11,783.87
6. Step 6: Final answer
   x = 7,668.70