Finding the Fourth Proportional to 2,547.91, 3,516.18 and 1,428.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,547.91 : 3,516.18 = 1,428.80 : x
2. Step 2: Convert to fraction form
   2,547.91/3,516.18 = 1,428.80/x
3. Step 3: Cross multiply
   2,547.91x = 3,516.18 × 1,428.80
4. Step 4: Simplify right side
   2,547.91x = 5,023,895.05
5. Step 5: Solve for x
   x = 5,023,895.05/2,547.91
6. Step 6: Final answer
   x = 1,971.77