Finding the Fourth Proportional to 91.83, 137.18 and 78.17

Step by Step Solution

1. Step 1: Write the proportion equation
   91.83 : 137.18 = 78.17 : x
2. Step 2: Convert to fraction form
   91.83/137.18 = 78.17/x
3. Step 3: Cross multiply
   91.83x = 137.18 × 78.17
4. Step 4: Simplify right side
   91.83x = 10,722.43
5. Step 5: Solve for x
   x = 10,722.43/91.83
6. Step 6: Final answer
   x = 116.76