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Finding the Fourth Proportional to 285.68, 428.26 and 129.39

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Solution

The fourth proportional to 285.68, 428.26 and 129.39 is: 193.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.68 : 428.26 = 129.39 : x
  2. Step 2: Convert to fraction form
    285.68/428.26 = 129.39/x
  3. Step 3: Cross multiply
    285.68x = 428.26 × 129.39
  4. Step 4: Simplify right side
    285.68x = 55,412.56
  5. Step 5: Solve for x
    x = 55,412.56/285.68
  6. Step 6: Final answer
    x = 193.97

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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.