Finding the Fourth Proportional to 42,779.98, 64,179.12 and 12,796.57

Step by Step Solution

1. Step 1: Write the proportion equation
   42,779.98 : 64,179.12 = 12,796.57 : x
2. Step 2: Convert to fraction form
   42,779.98/64,179.12 = 12,796.57/x
3. Step 3: Cross multiply
   42,779.98x = 64,179.12 × 12,796.57
4. Step 4: Simplify right side
   42,779.98x = 821,272,601.62
5. Step 5: Solve for x
   x = 821,272,601.62/42,779.98
6. Step 6: Final answer
   x = 19,197.59