Finding the Fourth Proportional to 42,788.64, 64,178.90 and 13,198.52

Step by Step Solution

1. Step 1: Write the proportion equation
   42,788.64 : 64,178.90 = 13,198.52 : x
2. Step 2: Convert to fraction form
   42,788.64/64,178.90 = 13,198.52/x
3. Step 3: Cross multiply
   42,788.64x = 64,178.90 × 13,198.52
4. Step 4: Simplify right side
   42,788.64x = 847,066,495.23
5. Step 5: Solve for x
   x = 847,066,495.23/42,788.64
6. Step 6: Final answer
   x = 19,796.53