Finding the Fourth Proportional to 42,790.64, 64,181.90 and 13,200.52

Step by Step Solution

1. Step 1: Write the proportion equation
   42,790.64 : 64,181.90 = 13,200.52 : x
2. Step 2: Convert to fraction form
   42,790.64/64,181.90 = 13,200.52/x
3. Step 3: Cross multiply
   42,790.64x = 64,181.90 × 13,200.52
4. Step 4: Simplify right side
   42,790.64x = 847,234,454.59
5. Step 5: Solve for x
   x = 847,234,454.59/42,790.64
6. Step 6: Final answer
   x = 19,799.53