Finding the Fourth Proportional to 10,915.12, 16,369.44 and 3,988

Step by Step Solution

1. Step 1: Write the proportion equation
   10,915.12 : 16,369.44 = 3,988 : x
2. Step 2: Convert to fraction form
   10,915.12/16,369.44 = 3,988/x
3. Step 3: Cross multiply
   10,915.12x = 16,369.44 × 3,988
4. Step 4: Simplify right side
   10,915.12x = 65,281,326.72
5. Step 5: Solve for x
   x = 65,281,326.72/10,915.12
6. Step 6: Final answer
   x = 5,980.82