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Finding the Fourth Proportional to 421.72, 627.83 and 419.68

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Solution

The fourth proportional to 421.72, 627.83 and 419.68 is: 624.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.72 : 627.83 = 419.68 : x
  2. Step 2: Convert to fraction form
    421.72/627.83 = 419.68/x
  3. Step 3: Cross multiply
    421.72x = 627.83 × 419.68
  4. Step 4: Simplify right side
    421.72x = 263,487.69
  5. Step 5: Solve for x
    x = 263,487.69/421.72
  6. Step 6: Final answer
    x = 624.79

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.