Finding the Fourth Proportional to 12,690.06, 17,510.20 and 7,971

Step by Step Solution

1. Step 1: Write the proportion equation
   12,690.06 : 17,510.20 = 7,971 : x
2. Step 2: Convert to fraction form
   12,690.06/17,510.20 = 7,971/x
3. Step 3: Cross multiply
   12,690.06x = 17,510.20 × 7,971
4. Step 4: Simplify right side
   12,690.06x = 139,573,804.20
5. Step 5: Solve for x
   x = 139,573,804.20/12,690.06
6. Step 6: Final answer
   x = 10,998.67