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Finding the Fourth Proportional to 685.13, 945.47 and 478.49

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Solution

The fourth proportional to 685.13, 945.47 and 478.49 is: 660.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.13 : 945.47 = 478.49 : x
  2. Step 2: Convert to fraction form
    685.13/945.47 = 478.49/x
  3. Step 3: Cross multiply
    685.13x = 945.47 × 478.49
  4. Step 4: Simplify right side
    685.13x = 452,394.41
  5. Step 5: Solve for x
    x = 452,394.41/685.13
  6. Step 6: Final answer
    x = 660.31

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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.