Finding the Fourth Proportional to 213,972.50, 321,012.05 and 64,215.59

Step by Step Solution

1. Step 1: Write the proportion equation
   213,972.50 : 321,012.05 = 64,215.59 : x
2. Step 2: Convert to fraction form
   213,972.50/321,012.05 = 64,215.59/x
3. Step 3: Cross multiply
   213,972.50x = 321,012.05 × 64,215.59
4. Step 4: Simplify right side
   213,972.50x = 20,613,976,261.72
5. Step 5: Solve for x
   x = 20,613,976,261.72/213,972.50
6. Step 6: Final answer
   x = 96,339.37