Finding the Fourth Proportional to 99.72, 149.60 and 83.72

Step by Step Solution

1. Step 1: Write the proportion equation
   99.72 : 149.60 = 83.72 : x
2. Step 2: Convert to fraction form
   99.72/149.60 = 83.72/x
3. Step 3: Cross multiply
   99.72x = 149.60 × 83.72
4. Step 4: Simplify right side
   99.72x = 12,524.51
5. Step 5: Solve for x
   x = 12,524.51/99.72
6. Step 6: Final answer
   x = 125.60