Finding the Fourth Proportional to 42,796.88, 64,184.28 and 12,805.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,796.88 : 64,184.28 = 12,805.20 : x
2. Step 2: Convert to fraction form
   42,796.88/64,184.28 = 12,805.20/x
3. Step 3: Cross multiply
   42,796.88x = 64,184.28 × 12,805.20
4. Step 4: Simplify right side
   42,796.88x = 821,892,542.26
5. Step 5: Solve for x
   x = 821,892,542.26/42,796.88
6. Step 6: Final answer
   x = 19,204.50