Finding the Fourth Proportional to 91.47, 137.41 and 53.05

Step by Step Solution

1. Step 1: Write the proportion equation
   91.47 : 137.41 = 53.05 : x
2. Step 2: Convert to fraction form
   91.47/137.41 = 53.05/x
3. Step 3: Cross multiply
   91.47x = 137.41 × 53.05
4. Step 4: Simplify right side
   91.47x = 7,288.91
5. Step 5: Solve for x
   x = 7,288.91/91.47
6. Step 6: Final answer
   x = 79.69