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Finding the Fourth Proportional to 814.40, 1,220.80 and 424.60

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Solution

The fourth proportional to 814.40, 1,220.80 and 424.60 is: 636.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.40 : 1,220.80 = 424.60 : x
  2. Step 2: Convert to fraction form
    814.40/1,220.80 = 424.60/x
  3. Step 3: Cross multiply
    814.40x = 1,220.80 × 424.60
  4. Step 4: Simplify right side
    814.40x = 518,351.68
  5. Step 5: Solve for x
    x = 518,351.68/814.40
  6. Step 6: Final answer
    x = 636.48

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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.