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Finding the Fourth Proportional to 646.85, 892.23 and 398.09

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Solution

The fourth proportional to 646.85, 892.23 and 398.09 is: 549.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.85 : 892.23 = 398.09 : x
  2. Step 2: Convert to fraction form
    646.85/892.23 = 398.09/x
  3. Step 3: Cross multiply
    646.85x = 892.23 × 398.09
  4. Step 4: Simplify right side
    646.85x = 355,183.38
  5. Step 5: Solve for x
    x = 355,183.38/646.85
  6. Step 6: Final answer
    x = 549.10

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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.