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Finding the Fourth Proportional to 678.13, 935.73 and 398.31

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Solution

The fourth proportional to 678.13, 935.73 and 398.31 is: 549.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.13 : 935.73 = 398.31 : x
  2. Step 2: Convert to fraction form
    678.13/935.73 = 398.31/x
  3. Step 3: Cross multiply
    678.13x = 935.73 × 398.31
  4. Step 4: Simplify right side
    678.13x = 372,710.62
  5. Step 5: Solve for x
    x = 372,710.62/678.13
  6. Step 6: Final answer
    x = 549.62

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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.