Finding the Fourth Proportional to 2,158.40, 2,978.80 and 1,274.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,158.40 : 2,978.80 = 1,274.48 : x
2. Step 2: Convert to fraction form
   2,158.40/2,978.80 = 1,274.48/x
3. Step 3: Cross multiply
   2,158.40x = 2,978.80 × 1,274.48
4. Step 4: Simplify right side
   2,158.40x = 3,796,421.02
5. Step 5: Solve for x
   x = 3,796,421.02/2,158.40
6. Step 6: Final answer
   x = 1,758.91