Finding the Fourth Proportional to 2,129.34, 2,938.56 and 1,290.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,129.34 : 2,938.56 = 1,290.20 : x
2. Step 2: Convert to fraction form
   2,129.34/2,938.56 = 1,290.20/x
3. Step 3: Cross multiply
   2,129.34x = 2,938.56 × 1,290.20
4. Step 4: Simplify right side
   2,129.34x = 3,791,330.11
5. Step 5: Solve for x
   x = 3,791,330.11/2,129.34
6. Step 6: Final answer
   x = 1,780.52