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Finding the Fourth Proportional to 499.87, 689.51 and 421.71

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Solution

The fourth proportional to 499.87, 689.51 and 421.71 is: 581.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.87 : 689.51 = 421.71 : x
  2. Step 2: Convert to fraction form
    499.87/689.51 = 421.71/x
  3. Step 3: Cross multiply
    499.87x = 689.51 × 421.71
  4. Step 4: Simplify right side
    499.87x = 290,771.73
  5. Step 5: Solve for x
    x = 290,771.73/499.87
  6. Step 6: Final answer
    x = 581.69

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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.