Finding the Fourth Proportional to 100,784.56, 139,036.16 and 64,986.07

Step by Step Solution

1. Step 1: Write the proportion equation
   100,784.56 : 139,036.16 = 64,986.07 : x
2. Step 2: Convert to fraction form
   100,784.56/139,036.16 = 64,986.07/x
3. Step 3: Cross multiply
   100,784.56x = 139,036.16 × 64,986.07
4. Step 4: Simplify right side
   100,784.56x = 9,035,412,606.18
5. Step 5: Solve for x
   x = 9,035,412,606.18/100,784.56
6. Step 6: Final answer
   x = 89,650.77