Finding the Fourth Proportional to 15,488.72, 21,374.70 and 8,415.15

Step by Step Solution

1. Step 1: Write the proportion equation
   15,488.72 : 21,374.70 = 8,415.15 : x
2. Step 2: Convert to fraction form
   15,488.72/21,374.70 = 8,415.15/x
3. Step 3: Cross multiply
   15,488.72x = 21,374.70 × 8,415.15
4. Step 4: Simplify right side
   15,488.72x = 179,871,306.71
5. Step 5: Solve for x
   x = 179,871,306.71/15,488.72
6. Step 6: Final answer
   x = 11,613.05