Finding the Fourth Proportional to 42,979.48, 64,483.23 and 21,621.17

Step by Step Solution

1. Step 1: Write the proportion equation
   42,979.48 : 64,483.23 = 21,621.17 : x
2. Step 2: Convert to fraction form
   42,979.48/64,483.23 = 21,621.17/x
3. Step 3: Cross multiply
   42,979.48x = 64,483.23 × 21,621.17
4. Step 4: Simplify right side
   42,979.48x = 1,394,203,241.17
5. Step 5: Solve for x
   x = 1,394,203,241.17/42,979.48
6. Step 6: Final answer
   x = 32,438.81