Finding the Fourth Proportional to 1,012.34, 1,387.91 and 993.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.34 : 1,387.91 = 993.89 : x
2. Step 2: Convert to fraction form
   1,012.34/1,387.91 = 993.89/x
3. Step 3: Cross multiply
   1,012.34x = 1,387.91 × 993.89
4. Step 4: Simplify right side
   1,012.34x = 1,379,428.02
5. Step 5: Solve for x
   x = 1,379,428.02/1,012.34
6. Step 6: Final answer
   x = 1,362.62