Finding the Fourth Proportional to 612,870.03, 919,308.96 and 213,518.25

Step by Step Solution

1. Step 1: Write the proportion equation
   612,870.03 : 919,308.96 = 213,518.25 : x
2. Step 2: Convert to fraction form
   612,870.03/919,308.96 = 213,518.25/x
3. Step 3: Cross multiply
   612,870.03x = 919,308.96 × 213,518.25
4. Step 4: Simplify right side
   612,870.03x = 196,289,240,348.52
5. Step 5: Solve for x
   x = 196,289,240,348.52/612,870.03
6. Step 6: Final answer
   x = 320,278.74