Finding the Fourth Proportional to 91.33, 136.59 and 78.37

Step by Step Solution

1. Step 1: Write the proportion equation
   91.33 : 136.59 = 78.37 : x
2. Step 2: Convert to fraction form
   91.33/136.59 = 78.37/x
3. Step 3: Cross multiply
   91.33x = 136.59 × 78.37
4. Step 4: Simplify right side
   91.33x = 10,704.56
5. Step 5: Solve for x
   x = 10,704.56/91.33
6. Step 6: Final answer
   x = 117.21