Finding the Fourth Proportional to 428,667.33, 643,035.96 and 215,325.48

Step by Step Solution

1. Step 1: Write the proportion equation
   428,667.33 : 643,035.96 = 215,325.48 : x
2. Step 2: Convert to fraction form
   428,667.33/643,035.96 = 215,325.48/x
3. Step 3: Cross multiply
   428,667.33x = 643,035.96 × 215,325.48
4. Step 4: Simplify right side
   428,667.33x = 138,462,026,744.26
5. Step 5: Solve for x
   x = 138,462,026,744.26/428,667.33
6. Step 6: Final answer
   x = 323,005.78