Finding the Fourth Proportional to 64,889.12, 89,561.40 and 42,188.72

Step by Step Solution

1. Step 1: Write the proportion equation
   64,889.12 : 89,561.40 = 42,188.72 : x
2. Step 2: Convert to fraction form
   64,889.12/89,561.40 = 42,188.72/x
3. Step 3: Cross multiply
   64,889.12x = 89,561.40 × 42,188.72
4. Step 4: Simplify right side
   64,889.12x = 3,778,480,827.41
5. Step 5: Solve for x
   x = 3,778,480,827.41/64,889.12
6. Step 6: Final answer
   x = 58,229.81