Finding the Fourth Proportional to 91.09, 136.01 and 78.27

Step by Step Solution

1. Step 1: Write the proportion equation
   91.09 : 136.01 = 78.27 : x
2. Step 2: Convert to fraction form
   91.09/136.01 = 78.27/x
3. Step 3: Cross multiply
   91.09x = 136.01 × 78.27
4. Step 4: Simplify right side
   91.09x = 10,645.50
5. Step 5: Solve for x
   x = 10,645.50/91.09
6. Step 6: Final answer
   x = 116.87