Finding the Fourth Proportional to 42,878.80, 64,308.42 and 19,173.88

Step by Step Solution

1. Step 1: Write the proportion equation
   42,878.80 : 64,308.42 = 19,173.88 : x
2. Step 2: Convert to fraction form
   42,878.80/64,308.42 = 19,173.88/x
3. Step 3: Cross multiply
   42,878.80x = 64,308.42 × 19,173.88
4. Step 4: Simplify right side
   42,878.80x = 1,233,041,928.07
5. Step 5: Solve for x
   x = 1,233,041,928.07/42,878.80
6. Step 6: Final answer
   x = 28,756.45