Finding the Fourth Proportional to 131.57, 181.59 and 90.16

Step by Step Solution

1. Step 1: Write the proportion equation
   131.57 : 181.59 = 90.16 : x
2. Step 2: Convert to fraction form
   131.57/181.59 = 90.16/x
3. Step 3: Cross multiply
   131.57x = 181.59 × 90.16
4. Step 4: Simplify right side
   131.57x = 16,372.89
5. Step 5: Solve for x
   x = 16,372.89/131.57
6. Step 6: Final answer
   x = 124.44