Finding the Fourth Proportional to 89,799.32, 133,638.72 and 86,809.34

Step by Step Solution

1. Step 1: Write the proportion equation
   89,799.32 : 133,638.72 = 86,809.34 : x
2. Step 2: Convert to fraction form
   89,799.32/133,638.72 = 86,809.34/x
3. Step 3: Cross multiply
   89,799.32x = 133,638.72 × 86,809.34
4. Step 4: Simplify right side
   89,799.32x = 11,601,089,081.64
5. Step 5: Solve for x
   x = 11,601,089,081.64/89,799.32
6. Step 6: Final answer
   x = 129,189.05