Finding the Fourth Proportional to 9,978.88, 14,962.56 and 4,128.96

Step by Step Solution

1. Step 1: Write the proportion equation
   9,978.88 : 14,962.56 = 4,128.96 : x
2. Step 2: Convert to fraction form
   9,978.88/14,962.56 = 4,128.96/x
3. Step 3: Cross multiply
   9,978.88x = 14,962.56 × 4,128.96
4. Step 4: Simplify right side
   9,978.88x = 61,779,811.74
5. Step 5: Solve for x
   x = 61,779,811.74/9,978.88
6. Step 6: Final answer
   x = 6,191.06