Finding the Fourth Proportional to 42,769.89, 64,147.95 and 12,783.69

Step by Step Solution

1. Step 1: Write the proportion equation
   42,769.89 : 64,147.95 = 12,783.69 : x
2. Step 2: Convert to fraction form
   42,769.89/64,147.95 = 12,783.69/x
3. Step 3: Cross multiply
   42,769.89x = 64,147.95 × 12,783.69
4. Step 4: Simplify right side
   42,769.89x = 820,047,506.94
5. Step 5: Solve for x
   x = 820,047,506.94/42,769.89
6. Step 6: Final answer
   x = 19,173.48