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Finding the Fourth Proportional to 491.97, 678.15 and 398.37

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Solution

The fourth proportional to 491.97, 678.15 and 398.37 is: 549.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.97 : 678.15 = 398.37 : x
  2. Step 2: Convert to fraction form
    491.97/678.15 = 398.37/x
  3. Step 3: Cross multiply
    491.97x = 678.15 × 398.37
  4. Step 4: Simplify right side
    491.97x = 270,154.62
  5. Step 5: Solve for x
    x = 270,154.62/491.97
  6. Step 6: Final answer
    x = 549.13

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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.