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Finding the Fourth Proportional to 521.34, 719.39 and 311.49

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Solution

The fourth proportional to 521.34, 719.39 and 311.49 is: 429.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.34 : 719.39 = 311.49 : x
  2. Step 2: Convert to fraction form
    521.34/719.39 = 311.49/x
  3. Step 3: Cross multiply
    521.34x = 719.39 × 311.49
  4. Step 4: Simplify right side
    521.34x = 224,083.57
  5. Step 5: Solve for x
    x = 224,083.57/521.34
  6. Step 6: Final answer
    x = 429.82

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Double scale
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Similar ratio
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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.