Finding the Fourth Proportional to 90.49, 136.34 and 78.34

Step by Step Solution

1. Step 1: Write the proportion equation
   90.49 : 136.34 = 78.34 : x
2. Step 2: Convert to fraction form
   90.49/136.34 = 78.34/x
3. Step 3: Cross multiply
   90.49x = 136.34 × 78.34
4. Step 4: Simplify right side
   90.49x = 10,680.29
5. Step 5: Solve for x
   x = 10,680.29/90.49
6. Step 6: Final answer
   x = 118.03