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Finding the Fourth Proportional to 641.92, 963.20 and 276.80

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Solution

The fourth proportional to 641.92, 963.20 and 276.80 is: 415.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.92 : 963.20 = 276.80 : x
  2. Step 2: Convert to fraction form
    641.92/963.20 = 276.80/x
  3. Step 3: Cross multiply
    641.92x = 963.20 × 276.80
  4. Step 4: Simplify right side
    641.92x = 266,613.76
  5. Step 5: Solve for x
    x = 266,613.76/641.92
  6. Step 6: Final answer
    x = 415.34

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.