Finding the Fourth Proportional to 6,889.72, 9,507.60 and 3,905.50

Step by Step Solution

1. Step 1: Write the proportion equation
   6,889.72 : 9,507.60 = 3,905.50 : x
2. Step 2: Convert to fraction form
   6,889.72/9,507.60 = 3,905.50/x
3. Step 3: Cross multiply
   6,889.72x = 9,507.60 × 3,905.50
4. Step 4: Simplify right side
   6,889.72x = 37,131,931.80
5. Step 5: Solve for x
   x = 37,131,931.80/6,889.72
6. Step 6: Final answer
   x = 5,389.47