Finding the Fourth Proportional to 78.63, 117.83 and 42.51

Step by Step Solution

1. Step 1: Write the proportion equation
   78.63 : 117.83 = 42.51 : x
2. Step 2: Convert to fraction form
   78.63/117.83 = 42.51/x
3. Step 3: Cross multiply
   78.63x = 117.83 × 42.51
4. Step 4: Simplify right side
   78.63x = 5,008.74
5. Step 5: Solve for x
   x = 5,008.74/78.63
6. Step 6: Final answer
   x = 63.70