Finding the Fourth Proportional to 52.51, 78.72 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   52.51 : 78.72 = 42.18 : x
2. Step 2: Convert to fraction form
   52.51/78.72 = 42.18/x
3. Step 3: Cross multiply
   52.51x = 78.72 × 42.18
4. Step 4: Simplify right side
   52.51x = 3,320.41
5. Step 5: Solve for x
   x = 3,320.41/52.51
6. Step 6: Final answer
   x = 63.23