Finding the Fourth Proportional to 42,879.37, 64,325.28 and 13,299.59

Step by Step Solution

1. Step 1: Write the proportion equation
   42,879.37 : 64,325.28 = 13,299.59 : x
2. Step 2: Convert to fraction form
   42,879.37/64,325.28 = 13,299.59/x
3. Step 3: Cross multiply
   42,879.37x = 64,325.28 × 13,299.59
4. Step 4: Simplify right side
   42,879.37x = 855,499,495.76
5. Step 5: Solve for x
   x = 855,499,495.76/42,879.37
6. Step 6: Final answer
   x = 19,951.31