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Finding the Fourth Proportional to 742.31, 1,112.89 and 280.07

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Solution

The fourth proportional to 742.31, 1,112.89 and 280.07 is: 419.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    742.31 : 1,112.89 = 280.07 : x
  2. Step 2: Convert to fraction form
    742.31/1,112.89 = 280.07/x
  3. Step 3: Cross multiply
    742.31x = 1,112.89 × 280.07
  4. Step 4: Simplify right side
    742.31x = 311,691.80
  5. Step 5: Solve for x
    x = 311,691.80/742.31
  6. Step 6: Final answer
    x = 419.89

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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.