Finding the Fourth Proportional to 100.50, 150.72 and 57.15

Step by Step Solution

1. Step 1: Write the proportion equation
   100.50 : 150.72 = 57.15 : x
2. Step 2: Convert to fraction form
   100.50/150.72 = 57.15/x
3. Step 3: Cross multiply
   100.50x = 150.72 × 57.15
4. Step 4: Simplify right side
   100.50x = 8,613.65
5. Step 5: Solve for x
   x = 8,613.65/100.50
6. Step 6: Final answer
   x = 85.71