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Finding the Fourth Proportional to 685.31, 945.64 and 419.87

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Solution

The fourth proportional to 685.31, 945.64 and 419.87 is: 579.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.31 : 945.64 = 419.87 : x
  2. Step 2: Convert to fraction form
    685.31/945.64 = 419.87/x
  3. Step 3: Cross multiply
    685.31x = 945.64 × 419.87
  4. Step 4: Simplify right side
    685.31x = 397,045.87
  5. Step 5: Solve for x
    x = 397,045.87/685.31
  6. Step 6: Final answer
    x = 579.37

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1.5x scale

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.