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Finding the Fourth Proportional to 513.61, 770.42 and 128.86

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Solution

The fourth proportional to 513.61, 770.42 and 128.86 is: 193.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    513.61 : 770.42 = 128.86 : x
  2. Step 2: Convert to fraction form
    513.61/770.42 = 128.86/x
  3. Step 3: Cross multiply
    513.61x = 770.42 × 128.86
  4. Step 4: Simplify right side
    513.61x = 99,276.32
  5. Step 5: Solve for x
    x = 99,276.32/513.61
  6. Step 6: Final answer
    x = 193.29

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Double scale
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Similar ratio
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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.