Finding the Fourth Proportional to 90.26, 136.10 and 78.38

Step by Step Solution

1. Step 1: Write the proportion equation
   90.26 : 136.10 = 78.38 : x
2. Step 2: Convert to fraction form
   90.26/136.10 = 78.38/x
3. Step 3: Cross multiply
   90.26x = 136.10 × 78.38
4. Step 4: Simplify right side
   90.26x = 10,667.52
5. Step 5: Solve for x
   x = 10,667.52/90.26
6. Step 6: Final answer
   x = 118.19