Finding the Fourth Proportional to 42,979.32, 64,469.43 and 12,993.82

Step by Step Solution

1. Step 1: Write the proportion equation
   42,979.32 : 64,469.43 = 12,993.82 : x
2. Step 2: Convert to fraction form
   42,979.32/64,469.43 = 12,993.82/x
3. Step 3: Cross multiply
   42,979.32x = 64,469.43 × 12,993.82
4. Step 4: Simplify right side
   42,979.32x = 837,704,007.75
5. Step 5: Solve for x
   x = 837,704,007.75/42,979.32
6. Step 6: Final answer
   x = 19,490.86