Finding the Fourth Proportional to 90.84, 136.15 and 42.02

Step by Step Solution

1. Step 1: Write the proportion equation
   90.84 : 136.15 = 42.02 : x
2. Step 2: Convert to fraction form
   90.84/136.15 = 42.02/x
3. Step 3: Cross multiply
   90.84x = 136.15 × 42.02
4. Step 4: Simplify right side
   90.84x = 5,721.69
5. Step 5: Solve for x
   x = 5,721.69/90.84
6. Step 6: Final answer
   x = 62.99