Finding the Fourth Proportional to 78,978.51, 118,469.31 and 19,812.65

Step by Step Solution

1. Step 1: Write the proportion equation
   78,978.51 : 118,469.31 = 19,812.65 : x
2. Step 2: Convert to fraction form
   78,978.51/118,469.31 = 19,812.65/x
3. Step 3: Cross multiply
   78,978.51x = 118,469.31 × 19,812.65
4. Step 4: Simplify right side
   78,978.51x = 2,347,190,382.42
5. Step 5: Solve for x
   x = 2,347,190,382.42/78,978.51
6. Step 6: Final answer
   x = 29,719.36