Finding the Fourth Proportional to 8,970.31, 12,378.72 and 4,991.59

Step by Step Solution

1. Step 1: Write the proportion equation
   8,970.31 : 12,378.72 = 4,991.59 : x
2. Step 2: Convert to fraction form
   8,970.31/12,378.72 = 4,991.59/x
3. Step 3: Cross multiply
   8,970.31x = 12,378.72 × 4,991.59
4. Step 4: Simplify right side
   8,970.31x = 61,789,494.96
5. Step 5: Solve for x
   x = 61,789,494.96/8,970.31
6. Step 6: Final answer
   x = 6,888.22