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Finding the Fourth Proportional to 639.76, 958.98 and 420.52

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Solution

The fourth proportional to 639.76, 958.98 and 420.52 is: 630.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.76 : 958.98 = 420.52 : x
  2. Step 2: Convert to fraction form
    639.76/958.98 = 420.52/x
  3. Step 3: Cross multiply
    639.76x = 958.98 × 420.52
  4. Step 4: Simplify right side
    639.76x = 403,270.27
  5. Step 5: Solve for x
    x = 403,270.27/639.76
  6. Step 6: Final answer
    x = 630.35

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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.