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Finding the Fourth Proportional to 641.71, 884.75 and 420.31

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Solution

The fourth proportional to 641.71, 884.75 and 420.31 is: 579.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.71 : 884.75 = 420.31 : x
  2. Step 2: Convert to fraction form
    641.71/884.75 = 420.31/x
  3. Step 3: Cross multiply
    641.71x = 884.75 × 420.31
  4. Step 4: Simplify right side
    641.71x = 371,869.27
  5. Step 5: Solve for x
    x = 371,869.27/641.71
  6. Step 6: Final answer
    x = 579.50

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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.