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Finding the Fourth Proportional to 641.59, 885.42 and 420.81

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Solution

The fourth proportional to 641.59, 885.42 and 420.81 is: 580.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.59 : 885.42 = 420.81 : x
  2. Step 2: Convert to fraction form
    641.59/885.42 = 420.81/x
  3. Step 3: Cross multiply
    641.59x = 885.42 × 420.81
  4. Step 4: Simplify right side
    641.59x = 372,590.27
  5. Step 5: Solve for x
    x = 372,590.27/641.59
  6. Step 6: Final answer
    x = 580.73

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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.