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Finding the Fourth Proportional to 685.80, 946.42 and 405.94

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Solution

The fourth proportional to 685.80, 946.42 and 405.94 is: 560.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.80 : 946.42 = 405.94 : x
  2. Step 2: Convert to fraction form
    685.80/946.42 = 405.94/x
  3. Step 3: Cross multiply
    685.80x = 946.42 × 405.94
  4. Step 4: Simplify right side
    685.80x = 384,189.73
  5. Step 5: Solve for x
    x = 384,189.73/685.80
  6. Step 6: Final answer
    x = 560.21

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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.