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Finding the Fourth Proportional to 712.81, 1,069.44 and 280

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Solution

The fourth proportional to 712.81, 1,069.44 and 280 is: 420.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.81 : 1,069.44 = 280 : x
  2. Step 2: Convert to fraction form
    712.81/1,069.44 = 280/x
  3. Step 3: Cross multiply
    712.81x = 1,069.44 × 280
  4. Step 4: Simplify right side
    712.81x = 299,443.20
  5. Step 5: Solve for x
    x = 299,443.20/712.81
  6. Step 6: Final answer
    x = 420.09

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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.