Finding the Fourth Proportional to 405,287.51, 559,300.91 and 221,531.33

Step by Step Solution

1. Step 1: Write the proportion equation
   405,287.51 : 559,300.91 = 221,531.33 : x
2. Step 2: Convert to fraction form
   405,287.51/559,300.91 = 221,531.33/x
3. Step 3: Cross multiply
   405,287.51x = 559,300.91 × 221,531.33
4. Step 4: Simplify right side
   405,287.51x = 123,902,670,558.35
5. Step 5: Solve for x
   x = 123,902,670,558.35/405,287.51
6. Step 6: Final answer
   x = 305,715.50