Finding the Fourth Proportional to 2,142, 2,956.20 and 1,210.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142 : 2,956.20 = 1,210.56 : x
2. Step 2: Convert to fraction form
   2,142/2,956.20 = 1,210.56/x
3. Step 3: Cross multiply
   2,142x = 2,956.20 × 1,210.56
4. Step 4: Simplify right side
   2,142x = 3,578,657.47
5. Step 5: Solve for x
   x = 3,578,657.47/2,142
6. Step 6: Final answer
   x = 1,670.71