Finding the Fourth Proportional to 42,802.72, 64,205.76 and 13,217.92

Step by Step Solution

1. Step 1: Write the proportion equation
   42,802.72 : 64,205.76 = 13,217.92 : x
2. Step 2: Convert to fraction form
   42,802.72/64,205.76 = 13,217.92/x
3. Step 3: Cross multiply
   42,802.72x = 64,205.76 × 13,217.92
4. Step 4: Simplify right side
   42,802.72x = 848,666,599.22
5. Step 5: Solve for x
   x = 848,666,599.22/42,802.72
6. Step 6: Final answer
   x = 19,827.40