Finding the Fourth Proportional to 215.47, 322.69 and 123.89

Step by Step Solution

1. Step 1: Write the proportion equation
   215.47 : 322.69 = 123.89 : x
2. Step 2: Convert to fraction form
   215.47/322.69 = 123.89/x
3. Step 3: Cross multiply
   215.47x = 322.69 × 123.89
4. Step 4: Simplify right side
   215.47x = 39,978.06
5. Step 5: Solve for x
   x = 39,978.06/215.47
6. Step 6: Final answer
   x = 185.54