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Finding the Fourth Proportional to 499.32, 687.87 and 420.48

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Solution

The fourth proportional to 499.32, 687.87 and 420.48 is: 579.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.32 : 687.87 = 420.48 : x
  2. Step 2: Convert to fraction form
    499.32/687.87 = 420.48/x
  3. Step 3: Cross multiply
    499.32x = 687.87 × 420.48
  4. Step 4: Simplify right side
    499.32x = 289,235.58
  5. Step 5: Solve for x
    x = 289,235.58/499.32
  6. Step 6: Final answer
    x = 579.26

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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.