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Finding the Fourth Proportional to 641.88, 885.23 and 420.91

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Solution

The fourth proportional to 641.88, 885.23 and 420.91 is: 580.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.88 : 885.23 = 420.91 : x
  2. Step 2: Convert to fraction form
    641.88/885.23 = 420.91/x
  3. Step 3: Cross multiply
    641.88x = 885.23 × 420.91
  4. Step 4: Simplify right side
    641.88x = 372,602.16
  5. Step 5: Solve for x
    x = 372,602.16/641.88
  6. Step 6: Final answer
    x = 580.49

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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.