Finding the Fourth Proportional to 83.30, 123.93 and 81.47

Step by Step Solution

1. Step 1: Write the proportion equation
   83.30 : 123.93 = 81.47 : x
2. Step 2: Convert to fraction form
   83.30/123.93 = 81.47/x
3. Step 3: Cross multiply
   83.30x = 123.93 × 81.47
4. Step 4: Simplify right side
   83.30x = 10,096.89
5. Step 5: Solve for x
   x = 10,096.89/83.30
6. Step 6: Final answer
   x = 121.22