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Finding the Fourth Proportional to 805.52, 1,207.56 and 420.68

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Solution

The fourth proportional to 805.52, 1,207.56 and 420.68 is: 630.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.52 : 1,207.56 = 420.68 : x
  2. Step 2: Convert to fraction form
    805.52/1,207.56 = 420.68/x
  3. Step 3: Cross multiply
    805.52x = 1,207.56 × 420.68
  4. Step 4: Simplify right side
    805.52x = 507,996.34
  5. Step 5: Solve for x
    x = 507,996.34/805.52
  6. Step 6: Final answer
    x = 630.64

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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.