Finding the Fourth Proportional to 42,792.27, 64,190.22 and 13,209.45

Step by Step Solution

1. Step 1: Write the proportion equation
   42,792.27 : 64,190.22 = 13,209.45 : x
2. Step 2: Convert to fraction form
   42,792.27/64,190.22 = 13,209.45/x
3. Step 3: Cross multiply
   42,792.27x = 64,190.22 × 13,209.45
4. Step 4: Simplify right side
   42,792.27x = 847,917,501.58
5. Step 5: Solve for x
   x = 847,917,501.58/42,792.27
6. Step 6: Final answer
   x = 19,814.74