Finding the Fourth Proportional to 1,012.74, 1,518.78 and 666.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.74 : 1,518.78 = 666.06 : x
2. Step 2: Convert to fraction form
   1,012.74/1,518.78 = 666.06/x
3. Step 3: Cross multiply
   1,012.74x = 1,518.78 × 666.06
4. Step 4: Simplify right side
   1,012.74x = 1,011,598.61
5. Step 5: Solve for x
   x = 1,011,598.61/1,012.74
6. Step 6: Final answer
   x = 998.87