Finding the Fourth Proportional to 42,792.18, 64,194.42 and 13,212.30

Step by Step Solution

1. Step 1: Write the proportion equation
   42,792.18 : 64,194.42 = 13,212.30 : x
2. Step 2: Convert to fraction form
   42,792.18/64,194.42 = 13,212.30/x
3. Step 3: Cross multiply
   42,792.18x = 64,194.42 × 13,212.30
4. Step 4: Simplify right side
   42,792.18x = 848,155,935.37
5. Step 5: Solve for x
   x = 848,155,935.37/42,792.18
6. Step 6: Final answer
   x = 19,820.35