Finding the Fourth Proportional to 99.67, 137.55 and 56.02

Step by Step Solution

1. Step 1: Write the proportion equation
   99.67 : 137.55 = 56.02 : x
2. Step 2: Convert to fraction form
   99.67/137.55 = 56.02/x
3. Step 3: Cross multiply
   99.67x = 137.55 × 56.02
4. Step 4: Simplify right side
   99.67x = 7,705.55
5. Step 5: Solve for x
   x = 7,705.55/99.67
6. Step 6: Final answer
   x = 77.31