Home / 2,138.80-3,207.28-821.76

Finding the Fourth Proportional to 2,138.80, 3,207.28 and 821.76

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Solution

The fourth proportional to 2,138.80, 3,207.28 and 821.76 is: 1,232.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,138.80 : 3,207.28 = 821.76 : x
  2. Step 2: Convert to fraction form
    2,138.80/3,207.28 = 821.76/x
  3. Step 3: Cross multiply
    2,138.80x = 3,207.28 × 821.76
  4. Step 4: Simplify right side
    2,138.80x = 2,635,614.41
  5. Step 5: Solve for x
    x = 2,635,614.41/2,138.80
  6. Step 6: Final answer
    x = 1,232.29

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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.