Finding the Fourth Proportional to 9,985.23, 13,779.70 and 5,509.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,985.23 : 13,779.70 = 5,509.30 : x
2. Step 2: Convert to fraction form
   9,985.23/13,779.70 = 5,509.30/x
3. Step 3: Cross multiply
   9,985.23x = 13,779.70 × 5,509.30
4. Step 4: Simplify right side
   9,985.23x = 75,916,478.82
5. Step 5: Solve for x
   x = 75,916,478.82/9,985.23
6. Step 6: Final answer
   x = 7,602.88