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Finding the Fourth Proportional to 685.65, 946.55 and 405.97

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Solution

The fourth proportional to 685.65, 946.55 and 405.97 is: 560.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.65 : 946.55 = 405.97 : x
  2. Step 2: Convert to fraction form
    685.65/946.55 = 405.97/x
  3. Step 3: Cross multiply
    685.65x = 946.55 × 405.97
  4. Step 4: Simplify right side
    685.65x = 384,270.90
  5. Step 5: Solve for x
    x = 384,270.90/685.65
  6. Step 6: Final answer
    x = 560.45

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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.