Finding the Fourth Proportional to 1,012.57, 1,521.69 and 988

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.57 : 1,521.69 = 988 : x
2. Step 2: Convert to fraction form
   1,012.57/1,521.69 = 988/x
3. Step 3: Cross multiply
   1,012.57x = 1,521.69 × 988
4. Step 4: Simplify right side
   1,012.57x = 1,503,429.72
5. Step 5: Solve for x
   x = 1,503,429.72/1,012.57
6. Step 6: Final answer
   x = 1,484.77