Finding the Fourth Proportional to 7,111.78, 10,668.15 and 3,989.44

Step by Step Solution

1. Step 1: Write the proportion equation
   7,111.78 : 10,668.15 = 3,989.44 : x
2. Step 2: Convert to fraction form
   7,111.78/10,668.15 = 3,989.44/x
3. Step 3: Cross multiply
   7,111.78x = 10,668.15 × 3,989.44
4. Step 4: Simplify right side
   7,111.78x = 42,559,944.34
5. Step 5: Solve for x
   x = 42,559,944.34/7,111.78
6. Step 6: Final answer
   x = 5,984.43