Finding the Fourth Proportional to 91.70, 137.37 and 42.89

Step by Step Solution

1. Step 1: Write the proportion equation
   91.70 : 137.37 = 42.89 : x
2. Step 2: Convert to fraction form
   91.70/137.37 = 42.89/x
3. Step 3: Cross multiply
   91.70x = 137.37 × 42.89
4. Step 4: Simplify right side
   91.70x = 5,891.80
5. Step 5: Solve for x
   x = 5,891.80/91.70
6. Step 6: Final answer
   x = 64.25