Finding the Fourth Proportional to 61.35, 91.98 and 42.21

Step by Step Solution

1. Step 1: Write the proportion equation
   61.35 : 91.98 = 42.21 : x
2. Step 2: Convert to fraction form
   61.35/91.98 = 42.21/x
3. Step 3: Cross multiply
   61.35x = 91.98 × 42.21
4. Step 4: Simplify right side
   61.35x = 3,882.48
5. Step 5: Solve for x
   x = 3,882.48/61.35
6. Step 6: Final answer
   x = 63.28