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Finding the Fourth Proportional to 685.14, 945.20 and 423

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Solution

The fourth proportional to 685.14, 945.20 and 423 is: 583.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.14 : 945.20 = 423 : x
  2. Step 2: Convert to fraction form
    685.14/945.20 = 423/x
  3. Step 3: Cross multiply
    685.14x = 945.20 × 423
  4. Step 4: Simplify right side
    685.14x = 399,817.49
  5. Step 5: Solve for x
    x = 399,817.49/685.14
  6. Step 6: Final answer
    x = 583.56

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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.