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Finding the Fourth Proportional to 814.62, 1,220.54 and 642.39

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Solution

The fourth proportional to 814.62, 1,220.54 and 642.39 is: 962.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.62 : 1,220.54 = 642.39 : x
  2. Step 2: Convert to fraction form
    814.62/1,220.54 = 642.39/x
  3. Step 3: Cross multiply
    814.62x = 1,220.54 × 642.39
  4. Step 4: Simplify right side
    814.62x = 784,059.48
  5. Step 5: Solve for x
    x = 784,059.48/814.62
  6. Step 6: Final answer
    x = 962.48

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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.