Finding the Fourth Proportional to 42,790.80, 64,040.40 and 42,790.80

Step by Step Solution

1. Step 1: Write the proportion equation
   42,790.80 : 64,040.40 = 42,790.80 : x
2. Step 2: Convert to fraction form
   42,790.80/64,040.40 = 42,790.80/x
3. Step 3: Cross multiply
   42,790.80x = 64,040.40 × 42,790.80
4. Step 4: Simplify right side
   42,790.80x = 2,740,339,948.32
5. Step 5: Solve for x
   x = 2,740,339,948.32/42,790.80
6. Step 6: Final answer
   x = 64,040.40