Finding the Fourth Proportional to 9,988.56, 14,988.78 and 5,308.38

Step by Step Solution

1. Step 1: Write the proportion equation
   9,988.56 : 14,988.78 = 5,308.38 : x
2. Step 2: Convert to fraction form
   9,988.56/14,988.78 = 5,308.38/x
3. Step 3: Cross multiply
   9,988.56x = 14,988.78 × 5,308.38
4. Step 4: Simplify right side
   9,988.56x = 79,566,139.98
5. Step 5: Solve for x
   x = 79,566,139.98/9,988.56
6. Step 6: Final answer
   x = 7,965.73