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Finding the Fourth Proportional to 513.03, 769.55 and 128.28

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Solution

The fourth proportional to 513.03, 769.55 and 128.28 is: 192.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    513.03 : 769.55 = 128.28 : x
  2. Step 2: Convert to fraction form
    513.03/769.55 = 128.28/x
  3. Step 3: Cross multiply
    513.03x = 769.55 × 128.28
  4. Step 4: Simplify right side
    513.03x = 98,717.87
  5. Step 5: Solve for x
    x = 98,717.87/513.03
  6. Step 6: Final answer
    x = 192.42

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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.