Finding the Fourth Proportional to 42,664.48, 64,003.76 and 13,079.36

Step by Step Solution

1. Step 1: Write the proportion equation
   42,664.48 : 64,003.76 = 13,079.36 : x
2. Step 2: Convert to fraction form
   42,664.48/64,003.76 = 13,079.36/x
3. Step 3: Cross multiply
   42,664.48x = 64,003.76 × 13,079.36
4. Step 4: Simplify right side
   42,664.48x = 837,128,218.39
5. Step 5: Solve for x
   x = 837,128,218.39/42,664.48
6. Step 6: Final answer
   x = 19,621.20