Finding the Fourth Proportional to 90.08, 123.38 and 85.10

Step by Step Solution

1. Step 1: Write the proportion equation
   90.08 : 123.38 = 85.10 : x
2. Step 2: Convert to fraction form
   90.08/123.38 = 85.10/x
3. Step 3: Cross multiply
   90.08x = 123.38 × 85.10
4. Step 4: Simplify right side
   90.08x = 10,499.64
5. Step 5: Solve for x
   x = 10,499.64/90.08
6. Step 6: Final answer
   x = 116.56