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Finding the Fourth Proportional to 678.31, 936.06 and 398.66

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Solution

The fourth proportional to 678.31, 936.06 and 398.66 is: 550.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.31 : 936.06 = 398.66 : x
  2. Step 2: Convert to fraction form
    678.31/936.06 = 398.66/x
  3. Step 3: Cross multiply
    678.31x = 936.06 × 398.66
  4. Step 4: Simplify right side
    678.31x = 373,163.50
  5. Step 5: Solve for x
    x = 373,163.50/678.31
  6. Step 6: Final answer
    x = 550.14

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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.