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Finding the Fourth Proportional to 639.20, 955.80 and 456.03

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Solution

The fourth proportional to 639.20, 955.80 and 456.03 is: 681.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.20 : 955.80 = 456.03 : x
  2. Step 2: Convert to fraction form
    639.20/955.80 = 456.03/x
  3. Step 3: Cross multiply
    639.20x = 955.80 × 456.03
  4. Step 4: Simplify right side
    639.20x = 435,873.47
  5. Step 5: Solve for x
    x = 435,873.47/639.20
  6. Step 6: Final answer
    x = 681.90

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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.