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Finding the Fourth Proportional to 821.28, 1,226.04 and 761.28

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Solution

The fourth proportional to 821.28, 1,226.04 and 761.28 is: 1,136.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.28 : 1,226.04 = 761.28 : x
  2. Step 2: Convert to fraction form
    821.28/1,226.04 = 761.28/x
  3. Step 3: Cross multiply
    821.28x = 1,226.04 × 761.28
  4. Step 4: Simplify right side
    821.28x = 933,359.73
  5. Step 5: Solve for x
    x = 933,359.73/821.28
  6. Step 6: Final answer
    x = 1,136.47

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.