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Finding the Fourth Proportional to 641.26, 885.07 and 420.13

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Solution

The fourth proportional to 641.26, 885.07 and 420.13 is: 579.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.26 : 885.07 = 420.13 : x
  2. Step 2: Convert to fraction form
    641.26/885.07 = 420.13/x
  3. Step 3: Cross multiply
    641.26x = 885.07 × 420.13
  4. Step 4: Simplify right side
    641.26x = 371,844.46
  5. Step 5: Solve for x
    x = 371,844.46/641.26
  6. Step 6: Final answer
    x = 579.87

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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.