Finding the Fourth Proportional to 42,821.78, 64,235.75 and 13,241.93

Step by Step Solution

1. Step 1: Write the proportion equation
   42,821.78 : 64,235.75 = 13,241.93 : x
2. Step 2: Convert to fraction form
   42,821.78/64,235.75 = 13,241.93/x
3. Step 3: Cross multiply
   42,821.78x = 64,235.75 × 13,241.93
4. Step 4: Simplify right side
   42,821.78x = 850,604,917.61
5. Step 5: Solve for x
   x = 850,604,917.61/42,821.78
6. Step 6: Final answer
   x = 19,863.84