Finding the Fourth Proportional to 99.72, 137.36 and 76.30

Step by Step Solution

1. Step 1: Write the proportion equation
   99.72 : 137.36 = 76.30 : x
2. Step 2: Convert to fraction form
   99.72/137.36 = 76.30/x
3. Step 3: Cross multiply
   99.72x = 137.36 × 76.30
4. Step 4: Simplify right side
   99.72x = 10,480.42
5. Step 5: Solve for x
   x = 10,480.42/99.72
6. Step 6: Final answer
   x = 105.10