Finding the Fourth Proportional to 99.89, 149.83 and 56.55

Step by Step Solution

1. Step 1: Write the proportion equation
   99.89 : 149.83 = 56.55 : x
2. Step 2: Convert to fraction form
   99.89/149.83 = 56.55/x
3. Step 3: Cross multiply
   99.89x = 149.83 × 56.55
4. Step 4: Simplify right side
   99.89x = 8,472.60
5. Step 5: Solve for x
   x = 8,472.60/99.89
6. Step 6: Final answer
   x = 84.82