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Finding the Fourth Proportional to 821.28, 1,231.92 and 437.28

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Solution

The fourth proportional to 821.28, 1,231.92 and 437.28 is: 655.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.28 : 1,231.92 = 437.28 : x
  2. Step 2: Convert to fraction form
    821.28/1,231.92 = 437.28/x
  3. Step 3: Cross multiply
    821.28x = 1,231.92 × 437.28
  4. Step 4: Simplify right side
    821.28x = 538,693.98
  5. Step 5: Solve for x
    x = 538,693.98/821.28
  6. Step 6: Final answer
    x = 655.92

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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.