Finding the Fourth Proportional to 91.37, 126.10 and 56.39

Step by Step Solution

1. Step 1: Write the proportion equation
   91.37 : 126.10 = 56.39 : x
2. Step 2: Convert to fraction form
   91.37/126.10 = 56.39/x
3. Step 3: Cross multiply
   91.37x = 126.10 × 56.39
4. Step 4: Simplify right side
   91.37x = 7,109.90
5. Step 5: Solve for x
   x = 7,109.90/91.37
6. Step 6: Final answer
   x = 77.82