Finding the Fourth Proportional to 612,411.98, 918,768.66 and 213,056.18

Step by Step Solution

1. Step 1: Write the proportion equation
   612,411.98 : 918,768.66 = 213,056.18 : x
2. Step 2: Convert to fraction form
   612,411.98/918,768.66 = 213,056.18/x
3. Step 3: Cross multiply
   612,411.98x = 918,768.66 × 213,056.18
4. Step 4: Simplify right side
   612,411.98x = 195,749,341,003.32
5. Step 5: Solve for x
   x = 195,749,341,003.32/612,411.98
6. Step 6: Final answer
   x = 319,636.69