Finding the Fourth Proportional to 42,801.55, 64,210.37 and 13,212.45

Step by Step Solution

1. Step 1: Write the proportion equation
   42,801.55 : 64,210.37 = 13,212.45 : x
2. Step 2: Convert to fraction form
   42,801.55/64,210.37 = 13,212.45/x
3. Step 3: Cross multiply
   42,801.55x = 64,210.37 × 13,212.45
4. Step 4: Simplify right side
   42,801.55x = 848,376,237.04
5. Step 5: Solve for x
   x = 848,376,237.04/42,801.55
6. Step 6: Final answer
   x = 19,821.16