Finding the Fourth Proportional to 15,123.20, 20,870.10 and 9,154.91

Step by Step Solution

1. Step 1: Write the proportion equation
   15,123.20 : 20,870.10 = 9,154.91 : x
2. Step 2: Convert to fraction form
   15,123.20/20,870.10 = 9,154.91/x
3. Step 3: Cross multiply
   15,123.20x = 20,870.10 × 9,154.91
4. Step 4: Simplify right side
   15,123.20x = 191,063,782.84
5. Step 5: Solve for x
   x = 191,063,782.84/15,123.20
6. Step 6: Final answer
   x = 12,633.82