Finding the Fourth Proportional to 91,770.21, 137,638.89 and 58,391.15

Step by Step Solution

1. Step 1: Write the proportion equation
   91,770.21 : 137,638.89 = 58,391.15 : x
2. Step 2: Convert to fraction form
   91,770.21/137,638.89 = 58,391.15/x
3. Step 3: Cross multiply
   91,770.21x = 137,638.89 × 58,391.15
4. Step 4: Simplify right side
   91,770.21x = 8,036,892,383.63
5. Step 5: Solve for x
   x = 8,036,892,383.63/91,770.21
6. Step 6: Final answer
   x = 87,576.27