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Finding the Fourth Proportional to 513.56, 770.34 and 128.81

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Solution

The fourth proportional to 513.56, 770.34 and 128.81 is: 193.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    513.56 : 770.34 = 128.81 : x
  2. Step 2: Convert to fraction form
    513.56/770.34 = 128.81/x
  3. Step 3: Cross multiply
    513.56x = 770.34 × 128.81
  4. Step 4: Simplify right side
    513.56x = 99,229.90
  5. Step 5: Solve for x
    x = 99,229.90/513.56
  6. Step 6: Final answer
    x = 193.22

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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.