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Finding the Fourth Proportional to 610.71, 842.90 and 398.30

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Solution

The fourth proportional to 610.71, 842.90 and 398.30 is: 549.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    610.71 : 842.90 = 398.30 : x
  2. Step 2: Convert to fraction form
    610.71/842.90 = 398.30/x
  3. Step 3: Cross multiply
    610.71x = 842.90 × 398.30
  4. Step 4: Simplify right side
    610.71x = 335,720.86
  5. Step 5: Solve for x
    x = 335,720.86/610.71
  6. Step 6: Final answer
    x = 549.73

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.