Finding the Fourth Proportional to 91.42, 137.06 and 78.52

Step by Step Solution

1. Step 1: Write the proportion equation
   91.42 : 137.06 = 78.52 : x
2. Step 2: Convert to fraction form
   91.42/137.06 = 78.52/x
3. Step 3: Cross multiply
   91.42x = 137.06 × 78.52
4. Step 4: Simplify right side
   91.42x = 10,761.95
5. Step 5: Solve for x
   x = 10,761.95/91.42
6. Step 6: Final answer
   x = 117.72