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Finding the Fourth Proportional to 641.76, 954.96 and 639.60

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Solution

The fourth proportional to 641.76, 954.96 and 639.60 is: 951.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.76 : 954.96 = 639.60 : x
  2. Step 2: Convert to fraction form
    641.76/954.96 = 639.60/x
  3. Step 3: Cross multiply
    641.76x = 954.96 × 639.60
  4. Step 4: Simplify right side
    641.76x = 610,792.42
  5. Step 5: Solve for x
    x = 610,792.42/641.76
  6. Step 6: Final answer
    x = 951.75

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.