Finding the Fourth Proportional to 1,012.30, 1,379.33 and 989.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.30 : 1,379.33 = 989.82 : x
2. Step 2: Convert to fraction form
   1,012.30/1,379.33 = 989.82/x
3. Step 3: Cross multiply
   1,012.30x = 1,379.33 × 989.82
4. Step 4: Simplify right side
   1,012.30x = 1,365,287.18
5. Step 5: Solve for x
   x = 1,365,287.18/1,012.30
6. Step 6: Final answer
   x = 1,348.70