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Finding the Fourth Proportional to 685.53, 945.72 and 419.89

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Solution

The fourth proportional to 685.53, 945.72 and 419.89 is: 579.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.53 : 945.72 = 419.89 : x
  2. Step 2: Convert to fraction form
    685.53/945.72 = 419.89/x
  3. Step 3: Cross multiply
    685.53x = 945.72 × 419.89
  4. Step 4: Simplify right side
    685.53x = 397,096.27
  5. Step 5: Solve for x
    x = 397,096.27/685.53
  6. Step 6: Final answer
    x = 579.25

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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.