Finding the Fourth Proportional to 91.59, 137.86 and 64.72

Step by Step Solution

1. Step 1: Write the proportion equation
   91.59 : 137.86 = 64.72 : x
2. Step 2: Convert to fraction form
   91.59/137.86 = 64.72/x
3. Step 3: Cross multiply
   91.59x = 137.86 × 64.72
4. Step 4: Simplify right side
   91.59x = 8,922.30
5. Step 5: Solve for x
   x = 8,922.30/91.59
6. Step 6: Final answer
   x = 97.42