Finding the Fourth Proportional to 13,978.72, 20,975.32 and 7,737.60

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.72 : 20,975.32 = 7,737.60 : x
2. Step 2: Convert to fraction form
   13,978.72/20,975.32 = 7,737.60/x
3. Step 3: Cross multiply
   13,978.72x = 20,975.32 × 7,737.60
4. Step 4: Simplify right side
   13,978.72x = 162,298,636.03
5. Step 5: Solve for x
   x = 162,298,636.03/13,978.72
6. Step 6: Final answer
   x = 11,610.41