Finding the Fourth Proportional to 62.90, 86.82 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   62.90 : 86.82 = 42.18 : x
2. Step 2: Convert to fraction form
   62.90/86.82 = 42.18/x
3. Step 3: Cross multiply
   62.90x = 86.82 × 42.18
4. Step 4: Simplify right side
   62.90x = 3,662.07
5. Step 5: Solve for x
   x = 3,662.07/62.90
6. Step 6: Final answer
   x = 58.22