Finding the Fourth Proportional to 15,287.28, 21,096.52 and 9,978.96

Step by Step Solution

1. Step 1: Write the proportion equation
   15,287.28 : 21,096.52 = 9,978.96 : x
2. Step 2: Convert to fraction form
   15,287.28/21,096.52 = 9,978.96/x
3. Step 3: Cross multiply
   15,287.28x = 21,096.52 × 9,978.96
4. Step 4: Simplify right side
   15,287.28x = 210,521,329.22
5. Step 5: Solve for x
   x = 210,521,329.22/15,287.28
6. Step 6: Final answer
   x = 13,771.01