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Finding the Fourth Proportional to 345.78, 518.67 and 129.42

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Solution

The fourth proportional to 345.78, 518.67 and 129.42 is: 194.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    345.78 : 518.67 = 129.42 : x
  2. Step 2: Convert to fraction form
    345.78/518.67 = 129.42/x
  3. Step 3: Cross multiply
    345.78x = 518.67 × 129.42
  4. Step 4: Simplify right side
    345.78x = 67,126.27
  5. Step 5: Solve for x
    x = 67,126.27/345.78
  6. Step 6: Final answer
    x = 194.13

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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.