Finding the Fourth Proportional to 91.08, 136.50 and 42.88

Step by Step Solution

1. Step 1: Write the proportion equation
   91.08 : 136.50 = 42.88 : x
2. Step 2: Convert to fraction form
   91.08/136.50 = 42.88/x
3. Step 3: Cross multiply
   91.08x = 136.50 × 42.88
4. Step 4: Simplify right side
   91.08x = 5,852.22
5. Step 5: Solve for x
   x = 5,852.22/91.08
6. Step 6: Final answer
   x = 64.26