Home / 1,687.20-2,529.48-821.28

Finding the Fourth Proportional to 1,687.20, 2,529.48 and 821.28

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Solution

The fourth proportional to 1,687.20, 2,529.48 and 821.28 is: 1,231.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,687.20 : 2,529.48 = 821.28 : x
  2. Step 2: Convert to fraction form
    1,687.20/2,529.48 = 821.28/x
  3. Step 3: Cross multiply
    1,687.20x = 2,529.48 × 821.28
  4. Step 4: Simplify right side
    1,687.20x = 2,077,411.33
  5. Step 5: Solve for x
    x = 2,077,411.33/1,687.20
  6. Step 6: Final answer
    x = 1,231.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.