Finding the Fourth Proportional to 56.67, 78.28 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   56.67 : 78.28 = 42.18 : x
2. Step 2: Convert to fraction form
   56.67/78.28 = 42.18/x
3. Step 3: Cross multiply
   56.67x = 78.28 × 42.18
4. Step 4: Simplify right side
   56.67x = 3,301.74
5. Step 5: Solve for x
   x = 3,301.74/56.67
6. Step 6: Final answer
   x = 58.26