Finding the Fourth Proportional to 9,638.78, 13,301.28 and 5,389.88

Step by Step Solution

1. Step 1: Write the proportion equation
   9,638.78 : 13,301.28 = 5,389.88 : x
2. Step 2: Convert to fraction form
   9,638.78/13,301.28 = 5,389.88/x
3. Step 3: Cross multiply
   9,638.78x = 13,301.28 × 5,389.88
4. Step 4: Simplify right side
   9,638.78x = 71,692,303.05
5. Step 5: Solve for x
   x = 71,692,303.05/9,638.78
6. Step 6: Final answer
   x = 7,437.90