Finding the Fourth Proportional to 13,900.72, 19,178.20 and 7,928.08

Step by Step Solution

1. Step 1: Write the proportion equation
   13,900.72 : 19,178.20 = 7,928.08 : x
2. Step 2: Convert to fraction form
   13,900.72/19,178.20 = 7,928.08/x
3. Step 3: Cross multiply
   13,900.72x = 19,178.20 × 7,928.08
4. Step 4: Simplify right side
   13,900.72x = 152,046,303.86
5. Step 5: Solve for x
   x = 152,046,303.86/13,900.72
6. Step 6: Final answer
   x = 10,938.02