Finding the Fourth Proportional to 10,912, 16,374.56 and 3,987.20

Step by Step Solution

1. Step 1: Write the proportion equation
   10,912 : 16,374.56 = 3,987.20 : x
2. Step 2: Convert to fraction form
   10,912/16,374.56 = 3,987.20/x
3. Step 3: Cross multiply
   10,912x = 16,374.56 × 3,987.20
4. Step 4: Simplify right side
   10,912x = 65,288,645.63
5. Step 5: Solve for x
   x = 65,288,645.63/10,912
6. Step 6: Final answer
   x = 5,983.20