Finding the Fourth Proportional to 42,778.20, 64,174.56 and 13,190.52

Step by Step Solution

1. Step 1: Write the proportion equation
   42,778.20 : 64,174.56 = 13,190.52 : x
2. Step 2: Convert to fraction form
   42,778.20/64,174.56 = 13,190.52/x
3. Step 3: Cross multiply
   42,778.20x = 64,174.56 × 13,190.52
4. Step 4: Simplify right side
   42,778.20x = 846,495,817.17
5. Step 5: Solve for x
   x = 846,495,817.17/42,778.20
6. Step 6: Final answer
   x = 19,788.02