Finding the Fourth Proportional to 1,531.72, 2,113.86 and 1,428.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,531.72 : 2,113.86 = 1,428.04 : x
2. Step 2: Convert to fraction form
   1,531.72/2,113.86 = 1,428.04/x
3. Step 3: Cross multiply
   1,531.72x = 2,113.86 × 1,428.04
4. Step 4: Simplify right side
   1,531.72x = 3,018,676.63
5. Step 5: Solve for x
   x = 3,018,676.63/1,531.72
6. Step 6: Final answer
   x = 1,970.78