Finding the Fourth Proportional to 123.89, 170.97 and 72.14

Step by Step Solution

1. Step 1: Write the proportion equation
   123.89 : 170.97 = 72.14 : x
2. Step 2: Convert to fraction form
   123.89/170.97 = 72.14/x
3. Step 3: Cross multiply
   123.89x = 170.97 × 72.14
4. Step 4: Simplify right side
   123.89x = 12,333.78
5. Step 5: Solve for x
   x = 12,333.78/123.89
6. Step 6: Final answer
   x = 99.55