Finding the Fourth Proportional to 78,870.36, 118,171.92 and 47,640

Step by Step Solution

1. Step 1: Write the proportion equation
   78,870.36 : 118,171.92 = 47,640 : x
2. Step 2: Convert to fraction form
   78,870.36/118,171.92 = 47,640/x
3. Step 3: Cross multiply
   78,870.36x = 118,171.92 × 47,640
4. Step 4: Simplify right side
   78,870.36x = 5,629,710,268.80
5. Step 5: Solve for x
   x = 5,629,710,268.80/78,870.36
6. Step 6: Final answer
   x = 71,379.29