Finding the Fourth Proportional to 99.69, 137.57 and 56.02

Step by Step Solution

1. Step 1: Write the proportion equation
   99.69 : 137.57 = 56.02 : x
2. Step 2: Convert to fraction form
   99.69/137.57 = 56.02/x
3. Step 3: Cross multiply
   99.69x = 137.57 × 56.02
4. Step 4: Simplify right side
   99.69x = 7,707.12
5. Step 5: Solve for x
   x = 7,707.12/99.69
6. Step 6: Final answer
   x = 77.31