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Finding the Fourth Proportional to 646.72, 892.55 and 398.22

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Solution

The fourth proportional to 646.72, 892.55 and 398.22 is: 549.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.72 : 892.55 = 398.22 : x
  2. Step 2: Convert to fraction form
    646.72/892.55 = 398.22/x
  3. Step 3: Cross multiply
    646.72x = 892.55 × 398.22
  4. Step 4: Simplify right side
    646.72x = 355,428.91
  5. Step 5: Solve for x
    x = 355,428.91/646.72
  6. Step 6: Final answer
    x = 549.59

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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.