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Finding the Fourth Proportional to 499.57, 687.89 and 421.00

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Solution

The fourth proportional to 499.57, 687.89 and 421.00 is: 579.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.57 : 687.89 = 421.00 : x
  2. Step 2: Convert to fraction form
    499.57/687.89 = 421.00/x
  3. Step 3: Cross multiply
    499.57x = 687.89 × 421.00
  4. Step 4: Simplify right side
    499.57x = 289,601.02
  5. Step 5: Solve for x
    x = 289,601.02/499.57
  6. Step 6: Final answer
    x = 579.70

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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.