Finding the Fourth Proportional to 42,686.37, 64,015.71 and 14,215.74

Step by Step Solution

1. Step 1: Write the proportion equation
   42,686.37 : 64,015.71 = 14,215.74 : x
2. Step 2: Convert to fraction form
   42,686.37/64,015.71 = 14,215.74/x
3. Step 3: Cross multiply
   42,686.37x = 64,015.71 × 14,215.74
4. Step 4: Simplify right side
   42,686.37x = 910,030,689.28
5. Step 5: Solve for x
   x = 910,030,689.28/42,686.37
6. Step 6: Final answer
   x = 21,319.00