Finding the Fourth Proportional to 721,462.34, 995,647.38 and 399,167.21

Step by Step Solution

1. Step 1: Write the proportion equation
   721,462.34 : 995,647.38 = 399,167.21 : x
2. Step 2: Convert to fraction form
   721,462.34/995,647.38 = 399,167.21/x
3. Step 3: Cross multiply
   721,462.34x = 995,647.38 × 399,167.21
4. Step 4: Simplify right side
   721,462.34x = 397,429,786,818.41
5. Step 5: Solve for x
   x = 397,429,786,818.41/721,462.34
6. Step 6: Final answer
   x = 550,866.99