Finding the Fourth Proportional to 42,648.12, 63,886.50 and 21,236.31

Step by Step Solution

1. Step 1: Write the proportion equation
   42,648.12 : 63,886.50 = 21,236.31 : x
2. Step 2: Convert to fraction form
   42,648.12/63,886.50 = 21,236.31/x
3. Step 3: Cross multiply
   42,648.12x = 63,886.50 × 21,236.31
4. Step 4: Simplify right side
   42,648.12x = 1,356,713,518.82
5. Step 5: Solve for x
   x = 1,356,713,518.82/42,648.12
6. Step 6: Final answer
   x = 31,811.80