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Finding the Fourth Proportional to 742.71, 1,115.81 and 434.78

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Solution

The fourth proportional to 742.71, 1,115.81 and 434.78 is: 653.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    742.71 : 1,115.81 = 434.78 : x
  2. Step 2: Convert to fraction form
    742.71/1,115.81 = 434.78/x
  3. Step 3: Cross multiply
    742.71x = 1,115.81 × 434.78
  4. Step 4: Simplify right side
    742.71x = 485,129.93
  5. Step 5: Solve for x
    x = 485,129.93/742.71
  6. Step 6: Final answer
    x = 653.19

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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.