Finding the Fourth Proportional to 67.42, 100.58 and 61.21

Step by Step Solution

1. Step 1: Write the proportion equation
   67.42 : 100.58 = 61.21 : x
2. Step 2: Convert to fraction form
   67.42/100.58 = 61.21/x
3. Step 3: Cross multiply
   67.42x = 100.58 × 61.21
4. Step 4: Simplify right side
   67.42x = 6,156.50
5. Step 5: Solve for x
   x = 6,156.50/67.42
6. Step 6: Final answer
   x = 91.32