Finding the Fourth Proportional to 2,173.84, 3,000.30 and 1,290.09

Step by Step Solution

1. Step 1: Write the proportion equation
   2,173.84 : 3,000.30 = 1,290.09 : x
2. Step 2: Convert to fraction form
   2,173.84/3,000.30 = 1,290.09/x
3. Step 3: Cross multiply
   2,173.84x = 3,000.30 × 1,290.09
4. Step 4: Simplify right side
   2,173.84x = 3,870,657.03
5. Step 5: Solve for x
   x = 3,870,657.03/2,173.84
6. Step 6: Final answer
   x = 1,780.56