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Finding the Fourth Proportional to 456.12, 687.60 and 424.80

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Solution

The fourth proportional to 456.12, 687.60 and 424.80 is: 640.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    456.12 : 687.60 = 424.80 : x
  2. Step 2: Convert to fraction form
    456.12/687.60 = 424.80/x
  3. Step 3: Cross multiply
    456.12x = 687.60 × 424.80
  4. Step 4: Simplify right side
    456.12x = 292,092.48
  5. Step 5: Solve for x
    x = 292,092.48/456.12
  6. Step 6: Final answer
    x = 640.39

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.