Finding the Fourth Proportional to 42,471.42, 63,707.28 and 12,889.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,471.42 : 63,707.28 = 12,889.50 : x
2. Step 2: Convert to fraction form
   42,471.42/63,707.28 = 12,889.50/x
3. Step 3: Cross multiply
   42,471.42x = 63,707.28 × 12,889.50
4. Step 4: Simplify right side
   42,471.42x = 821,154,985.56
5. Step 5: Solve for x
   x = 821,154,985.56/42,471.42
6. Step 6: Final answer
   x = 19,334.30