Finding the Fourth Proportional to 42,664.62, 64,009.23 and 13,086.81

Step by Step Solution

1. Step 1: Write the proportion equation
   42,664.62 : 64,009.23 = 13,086.81 : x
2. Step 2: Convert to fraction form
   42,664.62/64,009.23 = 13,086.81/x
3. Step 3: Cross multiply
   42,664.62x = 64,009.23 × 13,086.81
4. Step 4: Simplify right side
   42,664.62x = 837,676,631.26
5. Step 5: Solve for x
   x = 837,676,631.26/42,664.62
6. Step 6: Final answer
   x = 19,633.99