Finding the Fourth Proportional to 100.99, 151.50 and 55.31

Step by Step Solution

1. Step 1: Write the proportion equation
   100.99 : 151.50 = 55.31 : x
2. Step 2: Convert to fraction form
   100.99/151.50 = 55.31/x
3. Step 3: Cross multiply
   100.99x = 151.50 × 55.31
4. Step 4: Simplify right side
   100.99x = 8,379.47
5. Step 5: Solve for x
   x = 8,379.47/100.99
6. Step 6: Final answer
   x = 82.98