Finding the Fourth Proportional to 93,139.56, 128,682.90 and 64,971

Step by Step Solution

1. Step 1: Write the proportion equation
   93,139.56 : 128,682.90 = 64,971 : x
2. Step 2: Convert to fraction form
   93,139.56/128,682.90 = 64,971/x
3. Step 3: Cross multiply
   93,139.56x = 128,682.90 × 64,971
4. Step 4: Simplify right side
   93,139.56x = 8,360,656,695.90
5. Step 5: Solve for x
   x = 8,360,656,695.90/93,139.56
6. Step 6: Final answer
   x = 89,764.83