Finding the Fourth Proportional to 91.09, 136.65 and 42.30

Step by Step Solution

1. Step 1: Write the proportion equation
   91.09 : 136.65 = 42.30 : x
2. Step 2: Convert to fraction form
   91.09/136.65 = 42.30/x
3. Step 3: Cross multiply
   91.09x = 136.65 × 42.30
4. Step 4: Simplify right side
   91.09x = 5,780.59
5. Step 5: Solve for x
   x = 5,780.59/91.09
6. Step 6: Final answer
   x = 63.46