Finding the Fourth Proportional to 2,547.40, 3,515.18 and 1,428.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,547.40 : 3,515.18 = 1,428.18 : x
2. Step 2: Convert to fraction form
   2,547.40/3,515.18 = 1,428.18/x
3. Step 3: Cross multiply
   2,547.40x = 3,515.18 × 1,428.18
4. Step 4: Simplify right side
   2,547.40x = 5,020,309.77
5. Step 5: Solve for x
   x = 5,020,309.77/2,547.40
6. Step 6: Final answer
   x = 1,970.76