Finding the Fourth Proportional to 13,665.78, 18,858.42 and 7,697.34

Step by Step Solution

1. Step 1: Write the proportion equation
   13,665.78 : 18,858.42 = 7,697.34 : x
2. Step 2: Convert to fraction form
   13,665.78/18,858.42 = 7,697.34/x
3. Step 3: Cross multiply
   13,665.78x = 18,858.42 × 7,697.34
4. Step 4: Simplify right side
   13,665.78x = 145,159,670.60
5. Step 5: Solve for x
   x = 145,159,670.60/13,665.78
6. Step 6: Final answer
   x = 10,622.13