Finding the Fourth Proportional to 99.63, 137.39 and 76.28

Step by Step Solution

1. Step 1: Write the proportion equation
   99.63 : 137.39 = 76.28 : x
2. Step 2: Convert to fraction form
   99.63/137.39 = 76.28/x
3. Step 3: Cross multiply
   99.63x = 137.39 × 76.28
4. Step 4: Simplify right side
   99.63x = 10,479.04
5. Step 5: Solve for x
   x = 10,479.04/99.63
6. Step 6: Final answer
   x = 105.18