Finding the Fourth Proportional to 39,972.69, 59,958.77 and 13,320.72

Step by Step Solution

1. Step 1: Write the proportion equation
   39,972.69 : 59,958.77 = 13,320.72 : x
2. Step 2: Convert to fraction form
   39,972.69/59,958.77 = 13,320.72/x
3. Step 3: Cross multiply
   39,972.69x = 59,958.77 × 13,320.72
4. Step 4: Simplify right side
   39,972.69x = 798,693,920.11
5. Step 5: Solve for x
   x = 798,693,920.11/39,972.69
6. Step 6: Final answer
   x = 19,980.99