Finding the Fourth Proportional to 12,991.72, 17,926.02 and 7,957

Step by Step Solution

1. Step 1: Write the proportion equation
   12,991.72 : 17,926.02 = 7,957 : x
2. Step 2: Convert to fraction form
   12,991.72/17,926.02 = 7,957/x
3. Step 3: Cross multiply
   12,991.72x = 17,926.02 × 7,957
4. Step 4: Simplify right side
   12,991.72x = 142,637,341.14
5. Step 5: Solve for x
   x = 142,637,341.14/12,991.72
6. Step 6: Final answer
   x = 10,979.10