Finding the Fourth Proportional to 105.18, 145.02 and 83.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105.18 : 145.02 = 83.30 : x
2. Step 2: Convert to fraction form
   105.18/145.02 = 83.30/x
3. Step 3: Cross multiply
   105.18x = 145.02 × 83.30
4. Step 4: Simplify right side
   105.18x = 12,080.17
5. Step 5: Solve for x
   x = 12,080.17/105.18
6. Step 6: Final answer
   x = 114.85