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Finding the Fourth Proportional to 685.62, 946.12 and 405.79

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Solution

The fourth proportional to 685.62, 946.12 and 405.79 is: 559.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.62 : 946.12 = 405.79 : x
  2. Step 2: Convert to fraction form
    685.62/946.12 = 405.79/x
  3. Step 3: Cross multiply
    685.62x = 946.12 × 405.79
  4. Step 4: Simplify right side
    685.62x = 383,926.03
  5. Step 5: Solve for x
    x = 383,926.03/685.62
  6. Step 6: Final answer
    x = 559.97

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1.5x scale

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.