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Finding the Fourth Proportional to 646.65, 892.11 and 397.88

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Solution

The fourth proportional to 646.65, 892.11 and 397.88 is: 548.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.65 : 892.11 = 397.88 : x
  2. Step 2: Convert to fraction form
    646.65/892.11 = 397.88/x
  3. Step 3: Cross multiply
    646.65x = 892.11 × 397.88
  4. Step 4: Simplify right side
    646.65x = 354,948.27
  5. Step 5: Solve for x
    x = 354,948.27/646.65
  6. Step 6: Final answer
    x = 548.90

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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.