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Finding the Fourth Proportional to 678.96, 937.18 and 399.31

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Solution

The fourth proportional to 678.96, 937.18 and 399.31 is: 551.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.96 : 937.18 = 399.31 : x
  2. Step 2: Convert to fraction form
    678.96/937.18 = 399.31/x
  3. Step 3: Cross multiply
    678.96x = 937.18 × 399.31
  4. Step 4: Simplify right side
    678.96x = 374,220.66
  5. Step 5: Solve for x
    x = 374,220.66/678.96
  6. Step 6: Final answer
    x = 551.17

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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.