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Finding the Fourth Proportional to 685.15, 945.49 and 419.54

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Solution

The fourth proportional to 685.15, 945.49 and 419.54 is: 578.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.15 : 945.49 = 419.54 : x
  2. Step 2: Convert to fraction form
    685.15/945.49 = 419.54/x
  3. Step 3: Cross multiply
    685.15x = 945.49 × 419.54
  4. Step 4: Simplify right side
    685.15x = 396,670.87
  5. Step 5: Solve for x
    x = 396,670.87/685.15
  6. Step 6: Final answer
    x = 578.95

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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.