Finding the Fourth Proportional to 42,840.33, 64,275.69 and 19,145.70

Step by Step Solution

1. Step 1: Write the proportion equation
   42,840.33 : 64,275.69 = 19,145.70 : x
2. Step 2: Convert to fraction form
   42,840.33/64,275.69 = 19,145.70/x
3. Step 3: Cross multiply
   42,840.33x = 64,275.69 × 19,145.70
4. Step 4: Simplify right side
   42,840.33x = 1,230,603,078.03
5. Step 5: Solve for x
   x = 1,230,603,078.03/42,840.33
6. Step 6: Final answer
   x = 28,725.34