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Finding the Fourth Proportional to 641.52, 885.54 and 420.66

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Solution

The fourth proportional to 641.52, 885.54 and 420.66 is: 580.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.52 : 885.54 = 420.66 : x
  2. Step 2: Convert to fraction form
    641.52/885.54 = 420.66/x
  3. Step 3: Cross multiply
    641.52x = 885.54 × 420.66
  4. Step 4: Simplify right side
    641.52x = 372,511.26
  5. Step 5: Solve for x
    x = 372,511.26/641.52
  6. Step 6: Final answer
    x = 580.67

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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.