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Finding the Fourth Proportional to 685.21, 945.22 and 419.79

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Solution

The fourth proportional to 685.21, 945.22 and 419.79 is: 579.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.21 : 945.22 = 419.79 : x
  2. Step 2: Convert to fraction form
    685.21/945.22 = 419.79/x
  3. Step 3: Cross multiply
    685.21x = 945.22 × 419.79
  4. Step 4: Simplify right side
    685.21x = 396,793.90
  5. Step 5: Solve for x
    x = 396,793.90/685.21
  6. Step 6: Final answer
    x = 579.08

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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.