Finding the Fourth Proportional to 91.33, 137.69 and 86.34

Step by Step Solution

1. Step 1: Write the proportion equation
   91.33 : 137.69 = 86.34 : x
2. Step 2: Convert to fraction form
   91.33/137.69 = 86.34/x
3. Step 3: Cross multiply
   91.33x = 137.69 × 86.34
4. Step 4: Simplify right side
   91.33x = 11,888.15
5. Step 5: Solve for x
   x = 11,888.15/91.33
6. Step 6: Final answer
   x = 130.17