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Finding the Fourth Proportional to 685.74, 1,029.18 and 480.72

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Solution

The fourth proportional to 685.74, 1,029.18 and 480.72 is: 721.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.74 : 1,029.18 = 480.72 : x
  2. Step 2: Convert to fraction form
    685.74/1,029.18 = 480.72/x
  3. Step 3: Cross multiply
    685.74x = 1,029.18 × 480.72
  4. Step 4: Simplify right side
    685.74x = 494,747.41
  5. Step 5: Solve for x
    x = 494,747.41/685.74
  6. Step 6: Final answer
    x = 721.48

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.