Finding the Fourth Proportional to 285,976.72, 428,968.28 and 86,299

Step by Step Solution

1. Step 1: Write the proportion equation
   285,976.72 : 428,968.28 = 86,299 : x
2. Step 2: Convert to fraction form
   285,976.72/428,968.28 = 86,299/x
3. Step 3: Cross multiply
   285,976.72x = 428,968.28 × 86,299
4. Step 4: Simplify right side
   285,976.72x = 37,019,533,595.72
5. Step 5: Solve for x
   x = 37,019,533,595.72/285,976.72
6. Step 6: Final answer
   x = 129,449.47