Finding the Fourth Proportional to 105,274.65, 145,278.72 and 57,528.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105,274.65 : 145,278.72 = 57,528.30 : x
2. Step 2: Convert to fraction form
   105,274.65/145,278.72 = 57,528.30/x
3. Step 3: Cross multiply
   105,274.65x = 145,278.72 × 57,528.30
4. Step 4: Simplify right side
   105,274.65x = 8,357,637,787.78
5. Step 5: Solve for x
   x = 8,357,637,787.78/105,274.65
6. Step 6: Final answer
   x = 79,388.89