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Finding the Fourth Proportional to 499.32, 687.96 and 420.66

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Solution

The fourth proportional to 499.32, 687.96 and 420.66 is: 579.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.32 : 687.96 = 420.66 : x
  2. Step 2: Convert to fraction form
    499.32/687.96 = 420.66/x
  3. Step 3: Cross multiply
    499.32x = 687.96 × 420.66
  4. Step 4: Simplify right side
    499.32x = 289,397.25
  5. Step 5: Solve for x
    x = 289,397.25/499.32
  6. Step 6: Final answer
    x = 579.58

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.