Finding the Fourth Proportional to 56.71, 78.24 and 42.19

Step by Step Solution

1. Step 1: Write the proportion equation
   56.71 : 78.24 = 42.19 : x
2. Step 2: Convert to fraction form
   56.71/78.24 = 42.19/x
3. Step 3: Cross multiply
   56.71x = 78.24 × 42.19
4. Step 4: Simplify right side
   56.71x = 3,300.95
5. Step 5: Solve for x
   x = 3,300.95/56.71
6. Step 6: Final answer
   x = 58.21