Finding the Fourth Proportional to 1,248.89, 1,870.41 and 987.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,248.89 : 1,870.41 = 987.13 : x
2. Step 2: Convert to fraction form
   1,248.89/1,870.41 = 987.13/x
3. Step 3: Cross multiply
   1,248.89x = 1,870.41 × 987.13
4. Step 4: Simplify right side
   1,248.89x = 1,846,337.82
5. Step 5: Solve for x
   x = 1,846,337.82/1,248.89
6. Step 6: Final answer
   x = 1,478.38