Finding the Fourth Proportional to 42,816.60, 64,226.72 and 13,235.00

Step by Step Solution

1. Step 1: Write the proportion equation
   42,816.60 : 64,226.72 = 13,235.00 : x
2. Step 2: Convert to fraction form
   42,816.60/64,226.72 = 13,235.00/x
3. Step 3: Cross multiply
   42,816.60x = 64,226.72 × 13,235.00
4. Step 4: Simplify right side
   42,816.60x = 850,040,351.15
5. Step 5: Solve for x
   x = 850,040,351.15/42,816.60
6. Step 6: Final answer
   x = 19,853.06