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Finding the Fourth Proportional to 639.99, 960.26 and 380.49

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Solution

The fourth proportional to 639.99, 960.26 and 380.49 is: 570.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.99 : 960.26 = 380.49 : x
  2. Step 2: Convert to fraction form
    639.99/960.26 = 380.49/x
  3. Step 3: Cross multiply
    639.99x = 960.26 × 380.49
  4. Step 4: Simplify right side
    639.99x = 365,363.82
  5. Step 5: Solve for x
    x = 365,363.82/639.99
  6. Step 6: Final answer
    x = 570.89

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Half scale
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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 (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.