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Finding the Fourth Proportional to 678.65, 936.57 and 398.97

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Solution

The fourth proportional to 678.65, 936.57 and 398.97 is: 550.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.65 : 936.57 = 398.97 : x
  2. Step 2: Convert to fraction form
    678.65/936.57 = 398.97/x
  3. Step 3: Cross multiply
    678.65x = 936.57 × 398.97
  4. Step 4: Simplify right side
    678.65x = 373,662.58
  5. Step 5: Solve for x
    x = 373,662.58/678.65
  6. Step 6: Final answer
    x = 550.60

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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.